New devtools test for named hooks verifying case when hooks are used …

…indirectly (facebook#21996)

## Summary
Adds a new unit test to `parseHookNames-test` which verifies that we correctly give names to hooks when they are used indirectly: 

e.g.
```
  const countState = useState(0);
  const count = countState[0];
  const setCount = countState[1];
``` 

Should produce `count` as the name.

## Test plan

```
yarn test
yarn test-build-devtools
yarn test-build-devtools parseHookNames
```

packages/react-devtools-extensions/src/__tests__/__source__/ComponentUsingHooksIndirectly.js

@@ -0,0 +1,44 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow
+ */
+
+import React, {useEffect, useState} from 'react';
+
+export function Component() {
+  const countState = useState(0);
+  const count = countState[0];
+  const setCount = countState[1];
+
+  const darkMode = useIsDarkMode();
+  const [isDarkMode] = darkMode;
+
+  useEffect(() => {
+    // ...
+  }, []);
+
+  const handleClick = () => setCount(count + 1);
+
+  return (
+    <>
+      <div>Dark mode? {isDarkMode}</div>
+      <div>Count: {count}</div>
+      <button onClick={handleClick}>Update count</button>
+    </>
+  );
+}
+
+function useIsDarkMode() {
+  const darkModeState = useState(false);
+  const [isDarkMode] = darkModeState;
+
+  useEffect(function useEffectCreate() {
+    // Here is where we may listen to a "theme" event...
+  }, []);
+
+  return [isDarkMode, () => {}];
+}