Update text selection when toggling checkbox

[amantoux]

When toggling a checkbox the cursor is set at the offset of the checkbox's line start

Fixes issues addressed by PR #400

[codecov]

Codecov Report

Attention: Patch coverage is 92.85714% with 1 line in your changes missing coverage. Please review.

Project coverage is 88.24%. Comparing base (6abce16) to head (f987e9d).
Report is 3 commits behind head on master.

Files with missing lines	Patch %	Lines
.../fleather/lib/src/widgets/editable_text_block.dart	91.66%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #441   +/-   ##
=======================================
  Coverage   88.24%   88.24%           
=======================================
  Files          62       62           
  Lines       10630    10640   +10     
=======================================
+ Hits         9380     9389    +9     
- Misses       1250     1251    +1     

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[amantoux]

@Amir-P can you please review?
Essentially, this allows the check box to render it's own state while silently updating the document via the controller.
This avoids the re-build of the editor that would scroll to the cursor position while preserving the current text selection.

[Amir-P]

Looks like not notifying listeners is causing issues with undoing.

Steps to reproduce:

1. Create a checklist
2. Toggle it
3. Press Cmd+Z
4. Press Cmd +Z

Expected Behavior: After pressing Cmd +Z for the first time checklist should be unchecked and pressing Cmd +Z one more time reverts checklist creation.

Actual Behavior: After pressing Cmd +Z for the first time nothing happens and pressing Cmd +Z one more time reverts checklist creation.

Screen.Recording.2025-01-01.at.11.09.36.mov

[amantoux]

Nice catch!
Can you please check the changes?

[Amir-P]

LGTM! Thanks!