Migrate cli-plugin-metro into repo

Summary:
## Context

RFC: Decoupling Flipper from React Native core: react-native-community/discussions-and-proposals#641

## Changes

Inits new package `react-native/cli-commands`. This migrates [`react-native-community/cli-plugin-metro`](https://github.com/react-native-community/cli/tree/main/packages/cli-plugin-metro) into the React Native repo, to enable faster iteration by the React Native core team. Specifically:

- This package contains several `metro` dependencies, which when removed from CLI will no longer require us to ship new CLI releases to get Metro patches and features to users.
- This package contains the `start`, `bundle`, and `ram-bundle` commands (central to the React Native development experience), for which we have incoming debugging-related changes.

The package source has been converted from TypeScript to Flow, with a number of new `flow-typed/` defs added to meet type coverage requirements.

## To dos

- For now, we aren't removing the existing [`react-native-community/cli-plugin-metro`](https://github.com/react-native-community/cli/tree/main/packages/cli-plugin-metro) source — until later PRs consolidate this move by changing dependencies in the `react-native` package.
- **Exported API is reduced!**: I'm working with szymonrybczak to decouple references from RN CLI packages react-native-community/cli#2021.

Changelog: [Internal]

Differential Revision: D46801501

fbshipit-source-id: 41cc4b77023654a926aa2fe6d439a502b296c1e7

flow-typed/npm/@react-native-community/cli-server-api_v12.x.x.js

@@ -0,0 +1,49 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict
+ * @format
+ * @oncall react_native
+ */
+
+declare module '@react-native-community/cli-server-api' {
+  import type {NextHandleFunction, Server} from 'connect';
+
+  declare type MiddlewareOptions = {
+    host?: string,
+    watchFolders: $ReadOnlyArray<string>,
+    port: number,
+  };
+
+  declare export function createDevServerMiddleware(
+    options: MiddlewareOptions,
+  ): {
+    middleware: Server,
+    websocketEndpoints: {
+      '/debugger-proxy': ws$WebSocketServer,
+      '/message': ws$WebSocketServer,
+      '/events': ws$WebSocketServer,
+    },
+    debuggerProxyEndpoint: {
+      server: ws$WebSocketServer,
+      isDebuggerConnected: () => boolean,
+    },
+    messageSocketEndpoint: {
+      server: ws$WebSocketServer,
+      broadcast: (
+        method: string,
+        params?: Record<string, mixed> | null,
+      ) => void,
+    },
+    eventsSocketEndpoint: {
+      server: ws$WebSocketServer,
+      reportEvent: (event: any) => void,
+    },
+    ...
+  };
+
+  declare export const indexPageMiddleware: NextHandleFunction;
+}

flow-typed/npm/@react-native-community/cli-tools_v12.x.x.js

@@ -0,0 +1,40 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict
+ * @format
+ * @oncall react_native
+ */
+
+declare module '@react-native-community/cli-tools' {
+  declare export class CLIError extends Error {
+    constructor(msg: string, originalError?: Error | mixed | string): this;
+  }
+
+  declare export function hookStdout(callback: Function): () => void;
+
+  declare export const logger: $ReadOnly<{
+    success: (...message: Array<string>) => void,
+    info: (...message: Array<string>) => void,
+    warn: (...message: Array<string>) => void,
+    error: (...message: Array<string>) => void,
+    debug: (...message: Array<string>) => void,
+    log: (...message: Array<string>) => void,
+    setVerbose: (level: boolean) => void,
+    isVerbose: () => boolean,
+    disable: () => void,
+    enable: () => void,
+  }>;
+
+  declare export function resolveNodeModuleDir(
+    root: string,
+    packageName: string,
+  ): string;
+
+  declare export const version: $ReadOnly<{
+    logIfUpdateAvailable: (projectRoot: string) => Promise<void>,
+  }>;
+}

flow-typed/npm/@react-native-community/cli-types_v12.x.x.js

@@ -0,0 +1,30 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow
+ * @format
+ * @oncall react_native
+ */
+
+declare module '@react-native-community/cli-types' {
+  declare type PlatformConfig = {
+    npmPackageName: string,
+    ...
+  };
+
+  declare export type Config = {
+    root: string,
+    reactNativePath: string,
+    reactNativeVersion: string,
+    project: Object,
+    platforms: {
+      android: PlatformConfig,
+      ios: PlatformConfig,
+      [name: string]: PlatformConfig,
+    },
+    ...
+  };
+}

flow-typed/npm/execa_v5.x.x.js

@@ -0,0 +1,118 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict
+ * @format
+ * @oncall react_native
+ */
+
+// Modified from flow-typed repo:
+// https://github.com/flow-typed/flow-typed/blob/master/definitions/npm/execa_v2.x.x/flow_v0.104.x-/execa_v2.x.x.js#L2
+
+declare module 'execa' {
+  declare type StdIoOption =
+    | 'pipe'
+    | 'ipc'
+    | 'ignore'
+    | 'inherit'
+    | stream$Stream
+    | number;
+
+  declare type CommonOptions = {
+    argv0?: string,
+    cleanup?: boolean,
+    cwd?: string,
+    detached?: boolean,
+    encoding?: string,
+    env?: {[string]: string | void, ...},
+    extendEnv?: boolean,
+    gid?: number,
+    killSignal?: string | number,
+    localDir?: string,
+    maxBuffer?: number,
+    preferLocal?: boolean,
+    reject?: boolean,
+    shell?: boolean | string,
+    stderr?: ?StdIoOption,
+    stdin?: ?StdIoOption,
+    stdio?: 'pipe' | 'ignore' | 'inherit' | $ReadOnlyArray<?StdIoOption>,
+    stdout?: ?StdIoOption,
+    stripEof?: boolean,
+    timeout?: number,
+    uid?: number,
+    windowsVerbatimArguments?: boolean,
+    buffer?: boolean,
+    all?: boolean,
+    stripFinalNewline?: boolean,
+  };
+
+  declare type SyncOptions = {
+    ...CommonOptions,
+    input?: string | Buffer,
+  };
+
+  declare type Options = {
+    ...CommonOptions,
+    input?: string | Buffer | stream$Readable,
+  };
+
+  declare type SyncResult = {
+    stdout: string,
+    stderr: string,
+    exitCode: number,
+    failed: boolean,
+    signal: ?string,
+    command: string,
+    timedOut: boolean,
+  };
+
+  declare type Result = {
+    ...SyncResult,
+    killed: boolean,
+  };
+
+  declare interface ExecaPromise
+    extends Promise<Result>,
+      child_process$ChildProcess {
+  }
+
+  declare interface ExecaError extends ErrnoError {
+    stdout: string;
+    stderr: string;
+    failed: boolean;
+    signal: ?string;
+    command: string;
+    timedOut: boolean;
+    exitCode: number;
+  }
+
+  declare interface Execa {
+    (
+      file: string,
+      args?: $ReadOnlyArray<string>,
+      options?: $ReadOnly<Options>,
+    ): ExecaPromise;
+    (file: string, options?: $ReadOnly<Options>): ExecaPromise;
+
+    command(command: string, options?: $ReadOnly<Options>): ExecaPromise;
+    commandSync(command: string, options?: $ReadOnly<Options>): ExecaPromise;
+
+    node(
+      path: string,
+      args?: $ReadOnlyArray<string>,
+      options?: $ReadOnly<Options>,
+    ): void;
+
+    sync(
+      file: string,
+      args?: $ReadOnlyArray<string>,
+      options?: $ReadOnly<SyncOptions>,
+    ): SyncResult;
+    sync(file: string, options?: $ReadOnly<SyncOptions>): SyncResult;
+  }
+
+  declare module.exports: Execa;
+}