Refactored PostTextEditor to use React Hook

[javidalkaruzi]

Description

See #22890

Refactored PostTextEditor to use React Hook.

How has this been tested?

Tested using existing unit tests.

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR.

[javidalkaruzi]

Hi @ntsekouras. When you have time, could you have another look at this pull request?

[ntsekouras]

Thanks for working on this! I left some small comments but I tested it and seems to be okay.

My main concern was about the getDerivedStateFromProps change. After consulting @youknowriad he noted these very useful things:

I think the difficulty in this component is due to the fact that we want:

1. Changes to the blocks (or the content property) in the store to reflect immediately in the editor
2. Changes in the editor to only change the blocks property when persisting and avoid parsing/serialization on each key strike

Reading the previous code getDerivedStateFromProps it seems to be used to update the state value (the rendered value) of the text editor when external changes happen (prop value changes) but only if we’re not editing the textarea (isdirty state)

I don’t think we should be too strict with keeping the exact same logic, but it’s definitely a fragile component that needs to be tested properly. (Autosaves should not impact editing, clearing the textarea should be possible, switching after edits updates the visual editor, clicking save after edits reflects the edits in the saved content, post is not dirty until we make an edit)

I have tested all the above and it LGTM compared to previous functionality on master.

[ntsekouras]

Thanks for your work @javidalkaruzi 👍