feat: improve keyboard behavior in mobile toolbar

[hyj1204]

To close #286

1. When there is no item menu on the screen, the toolbar will show _QuitEditingBtn to close the toolbar and keyboard.
2. When the item menu is on, the toolbar will show an 'X' icon button to close the menu and pop up keyboard
3. If the user clicks an action toolbar item(without a menu), it will close the current menu if it is on the screen.

Screen.Recording.2023-07-04.at.4.41.40.PM.mov

[codecov]

Codecov Report

Merging #287 (7ae1da9) into main (2b2bce4) will decrease coverage by 0.15%.
The diff coverage is 26.92%.

@@            Coverage Diff             @@
##             main     #287      +/-   ##
==========================================
- Coverage   68.42%   68.27%   -0.15%     
==========================================
  Files         240      239       -1     
  Lines       10168     9966     -202     
==========================================
- Hits         6957     6804     -153     
+ Misses       3211     3162      -49     

Impacted Files	Coverage Δ
...tor_component/service/keyboard_service_widget.dart	85.12% <0.00%> (-4.45%)	⬇️
..._items/color/background_color_options_widgets.dart	62.85% <ø> (-37.15%)	⬇️
...oolbar_items/color/text_color_options_widgets.dart	64.70% <ø> (-35.30%)	⬇️
lib/src/infra/mobile/af_mobile_icon.dart	87.50% <ø> (-12.50%)	⬇️
lib/src/editor/toolbar/mobile/mobile_toolbar.dart	73.40% <31.57%> (-22.85%)	⬇️
...rmat_single_character/format_single_character.dart	96.87% <100.00%> (ø)

... and 40 files with indirect coverage changes

[LucasXu0]

@hyj1204 Please check the CI.