Add Widget Dialog Fixes

[Gold872]

• Switching tabs while dragging no longer breaks everything
• Reorganized (and improved) add widget dialog

[codecov]

Codecov Report

Attention: Patch coverage is 76.25899% with 33 lines in your changes missing coverage. Please review.

Project coverage is 77.10%. Comparing base (9d2e0c7) to head (6bad22e).
Report is 1 commits behind head on main.

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
lib/pages/dashboard_page.dart	81.30%	20 Missing ⚠️
lib/widgets/network_tree/networktables_tree.dart	57.89%	8 Missing ⚠️
lib/widgets/dialog_widgets/layout_drag_tile.dart	42.85%	4 Missing ⚠️
lib/widgets/tab_grid.dart	83.33%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #193      +/-   ##
==========================================
- Coverage   77.21%   77.10%   -0.11%     
==========================================
  Files          80       80              
  Lines        8709     8733      +24     
==========================================
+ Hits         6725     6734       +9     
- Misses       1984     1999      +15     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.