refactor: major code restructuring

[ErikKalkoken]

The ui package has grown very large over time. This PR breaks it down into multiple smaller packages.

The (old) ui package has been split by feature into the following:

• assetui: asset widgets
• characterui: character widgets
• characterwindow: manage character window
• corporationui: corporation widgets
• gamesearchui: game search widgets / window
• industryui: industry widgets
• settingswindow: settings window
• skillui: skill widgets
• statuswindow: update status window
• ui (new): baseUI, desktopUI, mobileUI and desktop related widgets

[codecov]

Codecov Report

❌ Patch coverage is 6.53009% with 3650 lines in your changes missing coverage. Please review.
✅ Project coverage is 30.7%. Comparing base (8287bc8) to head (73ae6a7).
⚠️ Report is 70 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/app/infowindow/infowindow.go	0.0%	486 Missing ⚠️
internal/app/characterwindow/charactertags.go	0.0%	385 Missing ⚠️
internal/app/characterwindow/characteradmin.go	0.0%	229 Missing ⚠️
internal/app/infowindow/characterinfo.go	0.0%	215 Missing ⚠️
internal/app/characterservice/section.go	14.0%	177 Missing and 1 partial ⚠️
internal/app/infowindow/corporationinfo.go	0.0%	153 Missing ⚠️
internal/app/characterui/contracts.go	0.0%	105 Missing ⚠️
internal/app/assetui/assetsearch.go	0.0%	96 Missing ⚠️
internal/app/characterwindow/charactertraining.go	0.0%	95 Missing ⚠️
internal/app/corporationservice/section.go	10.4%	94 Missing ⚠️
... and 72 more

Additional details and impacted files

@@           Coverage Diff           @@
##            main    #415     +/-   ##
=======================================
- Coverage   34.3%   30.7%   -3.6%     
=======================================
  Files        254     273     +19     
  Lines      41077   41378    +301     
=======================================
- Hits       14102   12743   -1359     
- Misses     24798   26788   +1990     
+ Partials    2177    1847    -330     

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