RNAztec iOS: Fix removing content after dictation

[etoledom]

Fixes #673

This issue was originally fixed here #610, but it resurfaced.

The original fix was blocking the empty strings to be sent from textViewDidChange to the RN side, when UIKit was inserting the dictation text. That empty string was finally overwriting the content when it was sent back from RN to Native, since with an empty string, the JS side nullifies the eventCount.

I noticed that in this case, the same was happening on textViewDidChangeSelection, so using the same strategy there solved the problem.

As discussed in the original PR, this is not the best fix, but a better solution will probably involve all platforms. If this continue being an issue in the future, I'd suggest to give some time to find that better solution.

To test:

• Build and run the project.
• Create an empty paragraph block.
• Test the iOS dictation feature.
• Check that it behaves properly.

[pinarol]

hey @etoledom 👋 I tried testing this on the WPiOS app and there seems to be some problems:

1. it can’t write the whole word
2. caret position is messed up
3. dictation listening ends very early I don’t know why

(iPhone 6, iOS 12.0.1)

[etoledom]

Thank you for the review @pinarol !

I updated the PR from develop and it seems to fix that issue you mentioned. Testing on WPiOS it seemed necessary to update the JS Bundle, since the app was crashing without metro running, so I did that too.

I also opened a WPiOS PR for easier testing with a description of the original issue:
wordpress-mobile/WordPress-iOS#11198

[pinarol]

Works and looks pretty good ! 🎉

[etoledom]

Thank you!