Feat: Text and background color in mobile toolbar

[hyj1204]

Add textAndBackgroundColorMobileToolbarItem to the toolbar on mobile.

• It shows a menu to let users select the text or background color.
• The first button(ClearColorButton) is to clear the color(set to null).
• The color options menu can be scrollable if they are more than 8 options.

text.and.background.color.mov

Note:

• All the color options can be customized in MobileToolbar. Just set a List of ColorOption in textColorOptions or backgroundColorOptions. If it is null, the default color options locate in lib/src/editor/toolbar/mobile/mobile_toolbar.dart .
• The customized color options are used only on mobile for now. It will be applied on the desktop in a separate PR. Currently, the Desktop version is still using the color options in lib/src/editor/toolbar/utils/color_generators.dart
  [FR] Customized color options in color picker for Desktop  #234
• The height of the Tarbar View for the color options is a fixed height( 3 lines of buttons with spacing) for now. It may need to be improved in the future to fit better with a dynamic number of options.
  [FR] UI Improvement for color picker in mobile #235

[codecov]

Codecov Report

Merging #233 (0fffeb8) into main (03bc577) will decrease coverage by 0.15%.
The diff coverage is 80.98%.

@@            Coverage Diff             @@
##             main     #233      +/-   ##
==========================================
- Coverage   63.80%   63.66%   -0.15%     
==========================================
  Files         232      239       +7     
  Lines        9950    10551     +601     
==========================================
+ Hits         6349     6717     +368     
- Misses       3601     3834     +233     

Impacted Files	Coverage Δ
...editor/toolbar/desktop/items/color/color_menu.dart	0.00% <0.00%> (ø)
...itor/toolbar/desktop/items/color/color_picker.dart	80.74% <ø> (+0.49%)	⬆️
...mobile/toolbar_items/link_mobile_toolbar_item.dart	1.69% <0.00%> (-0.03%)	⬇️
lib/src/editor/toolbar/utils/color_generators.dart	0.00% <0.00%> (ø)
lib/src/infra/mobile/af_mobile_icon.dart	100.00% <ø> (ø)
...efault_text_operations/format_rich_text_style.dart	0.00% <ø> (ø)
lib/src/l10n/l10n.dart	45.60% <80.00%> (+2.30%)	⬆️
lib/src/editor/toolbar/mobile/mobile_toolbar.dart	96.38% <90.47%> (+0.38%)	⬆️
...rc/editor/toolbar/mobile/mobile_toolbar_style.dart	100.00% <100.00%> (ø)
..._items/color/background_color_options_widgets.dart	100.00% <100.00%> (ø)
... and 12 more

... and 39 files with indirect coverage changes