chore: dependency upgrades

[matthiasn]

• Upgrade Flutter to 3.16.5
• Upgrade all dependencies
• Use new editor version, add checklist items

[codecov]

Codecov Report

Attention: 26 lines in your changes are missing coverage. Please review.

Comparison is base (bb64d8a) 70.21% compared to head (cd0b719) 70.12%.
Report is 2 commits behind head on main.

Files	Patch %	Lines
lib/widgets/sync/imap_config.dart	0.00%	7 Missing ⚠️
...ets/journal/entry_details/entry_detail_header.dart	60.00%	6 Missing ⚠️
lib/sync/inbox/inbox_service_isolate.dart	0.00%	4 Missing ⚠️
lib/widgets/journal/editor/editor_widget.dart	86.66%	4 Missing ⚠️
lib/widgets/misc/map_widget.dart	20.00%	4 Missing ⚠️
lib/database/conversions.dart	90.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1639      +/-   ##
==========================================
- Coverage   70.21%   70.12%   -0.09%     
==========================================
  Files         269      269              
  Lines       10974    10939      -35     
==========================================
- Hits         7705     7671      -34     
+ Misses       3269     3268       -1     

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