Parse custom NativeState in Flow (facebook#34753)

Summary:
Pull Request resolved: facebook#34753

This Diff introduce a the capability to parse custom NativeStates in Flow. To achieve this I also had to define the CodegenSchema.

The parsing follows the exact same rules as props, as initial heuristic. This should allow enough customization for the developers who needs a custom state.

There is only a case I was not able to make it work that is STATE_ALIASED_LOCALLY, from the fixtures. I don't know how diffuse it is and I think we can live with some workarounds for the time being.

This diff also adds tests for the custom Native State Flow Parser.

## Changelog
[General][Added] - Implement custom Native State parsing in Flow

Differential Revision: https://internalfb.com/D39686251

fbshipit-source-id: 18b3e2973bdf20b4858d416cc934f8bfa3bdb538

packages/react-native-codegen/src/CodegenSchema.js

@@ -80,6 +80,7 @@ export type ComponentShape = $ReadOnly<{
   events: $ReadOnlyArray<EventTypeShape>,
   props: $ReadOnlyArray<NamedShape<PropTypeAnnotation>>,
   commands: $ReadOnlyArray<NamedShape<CommandTypeAnnotation>>,
+  state?: $ReadOnlyArray<NamedShape<StateTypeAnnotation>>,
 }>;
 
 export type OptionsShape = $ReadOnly<{
@@ -185,6 +186,8 @@ export type ReservedPropTypeAnnotation = $ReadOnly<{
     | 'EdgeInsetsPrimitive',
 }>;
 
+export type StateTypeAnnotation = PropTypeAnnotation;
+
 export type CommandTypeAnnotation = FunctionTypeAnnotation<
   CommandParamTypeAnnotation,
   VoidTypeAnnotation,

packages/react-native-codegen/src/parsers/consistency/__tests__/checkComponentSnaps-test.js

@@ -14,10 +14,19 @@ const {compareSnaps, compareTsArraySnaps} = require('../compareSnaps.js');
 
 const flowFixtures = require('../../flow/components/__test_fixtures__/fixtures.js');
 const flowSnaps = require('../../../../src/parsers/flow/components/__tests__/__snapshots__/component-parser-test.js.snap');
-const flowExtraCases = [];
+const flowExtraCases = [
+  //TODO: remove these once we implement TypeScript parser for Custom State
+  'ALL_STATE_TYPES',
+  'ARRAY_STATE_TYPES',
+  'COMMANDS_EVENTS_STATE_TYPES_EXPORTED',
+  'OBJECT_STATE_TYPES',
+];
 const tsFixtures = require('../../typescript/components/__test_fixtures__/fixtures.js');
 const tsSnaps = require('../../../../src/parsers/typescript/components/__tests__/__snapshots__/typescript-component-parser-test.js.snap');
-const tsExtraCases = ['ARRAY2_PROP_TYPES_NO_EVENTS'];
+const tsExtraCases = ['ARRAY2_PROP_TYPES_NO_EVENTS'].concat([
+  //TODO: remove these once we implement TypeScript parser for Custom State
+  'COMMANDS_AND_EVENTS_TYPES_EXPORTED',
+]);
 const ignoredCases = ['ARRAY_PROP_TYPES_NO_EVENTS'];
 
 compareSnaps(