* Update useEditableValue to mirror value cahnges
Previously, the hook initialized local state (in useState) to mirror the prop/state value. Updates to the value were ignored though. (Once the state was initialized, it was never updated.) The new hook updates the local/editable state to mirror the external value unless there are already pending, local edits being made.
* Optimistic CHANGELOG update
* Added additional useEditableValue() unit test cases
* [react-devtools-shared] Added string type check for object name prop in getDisplayName function from utils.js file; tests included;
* Re-added empty string check to getDisplayName()
* Tweaked tests to use real functions
This more closely simulates how the utility is being used in production, and would catch cases like anonymous functions (with empty string names).
Brian Vaughn