Focus management

[koke]

Creating this issue to group a few bugs related to focus that we want to address for the alpha:

• Tapping into RichText doesn't move the cursor properly on Android Tapping into RichText doesn't move the cursor properly on Android #135
• Inserting a new block doesn't make cursor immediately available on new block Inserter - cursor not following along focus when inserting a new block #113, Fix isSelected for RichText #270
  I think these two were estimated at 2 weeks
• Tapping into PlainText doesn't allow to select text / copy / paste Tapping into PlainText doesn't allow to select text on Android #267 doesn't apply as we move on using FlatList

Parting the case into more granular items here:

• Tapping into PlainText doesn't make the block-holder selected Tapping on PlainText powered blocks does not make the block-holder selected #251
• Implement InputTextState-like focus sync for Aztec Implement InputTextState-like focus sync mechanism for RCTAztecView #273
• Tapping into a block doesn't make the block selected Tapping into a block doesn't make the block selected #287
• RichText: when the caret is blinking, tapping on any inline toolbar action button (down/up, trash) does not work and instead makes the next available editable to get the focus [RichText]: when editable is focused, tapping on toolbar actions switches focus #292
• RichText: when toolbar is actionable (note it's different than being just shown), can't obtain focus on editable [RichText] when inline toolbar is actionable, can't obtain focus on editable #293
• Focus Loop when deleting content and blocks Focus Loop when deleting content and blocks  #302
• Pressing delete at the beginning of a block (and NO merge) moves the focus to the wrong block Pressing delete at the beginning of a block (and NO merge) moves the focus to the wrong block #306 (closed without fixig it for the alpha, but opened a new issue for the beta phase).
• Tapping on a Page Break block does make the block-holder selected but keep the keyboard up, and the caret to the Para block Tapping on a Page Break block does make the block-holder selected but keep the keyboard up, and the caret to the Para block #308
• Exclude EditPostActivity from handling orientation change for alpha WordPress-Android#8800 [Android only] Preserve scroll and caret position after rotating (Gutenberg Editor)

[koke]

I'm going to close this one, since #308 is about to land in master, and the rotation issues will be handled in the beta