feat: enable debug paint size for mobile drag handle

[LucasXu0]

Set editorState.debugInfo.debugPaintSizeEnabled to true to render the paint size for the mobile drag handle.

[codecov]

Codecov Report

Attention: Patch coverage is 19.04762% with 68 lines in your changes missing coverage. Please review.

Project coverage is 71.96%. Comparing base (c68e5f6) to head (a378286).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
.../src/render/selection/mobile_collapsed_handle.dart	0.00%	36 Missing ⚠️
...nt/service/selection/mobile_selection_service.dart	10.00%	18 Missing ⚠️
lib/src/render/selection/mobile_basic_handle.dart	0.00%	8 Missing ⚠️
...tor_component/service/ime/delta_input_service.dart	0.00%	2 Missing ⚠️
...component/service/ime/non_delta_input_service.dart	0.00%	2 Missing ⚠️
...rvice/ime/delta_input_on_non_text_update_impl.dart	0.00%	1 Missing ⚠️
...tor_component/service/keyboard_service_widget.dart	83.33%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1007      +/-   ##
==========================================
- Coverage   72.16%   71.96%   -0.21%     
==========================================
  Files         319      319              
  Lines       15246    15312      +66     
==========================================
+ Hits        11003    11019      +16     
- Misses       4243     4293      +50     

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[LucasXu0]

closes #1007