Detachable Unit Display Removal

[Windchild292]

This tears out the Detachable Unit Display and replaces it with (largely) the original code.
It replaces #3627, which kept having odd phase issues. By invalidation, this closes #3223, closes #3272, closes #3309, closes #3372, closes #3579, and closes #3616.

I will be following this up with an AbstractDialog rework (some baseline changes included) and Skin Editor dialog update immediately after 0.49.8.

[codecov]

Codecov Report

Merging #3629 (2a5f604) into master (4085fa8) will increase coverage by 0.00%.
The diff coverage is 0.64%.

@@            Coverage Diff            @@
##             master    #3629   +/-   ##
=========================================
  Coverage     23.75%   23.76%           
  Complexity     4878     4878           
=========================================
  Files          2199     2198    -1     
  Lines        242627   242540   -87     
  Branches      45454    45455    +1     
=========================================
- Hits          57643    57639    -4     
+ Misses       183501   183418   -83     
  Partials       1483     1483           

Impacted Files	Coverage Δ
...c/megamek/client/ui/dialogs/UnitDisplayDialog.java	0.00% <0.00%> (ø)
megamek/src/megamek/client/ui/swing/ClientGUI.java	0.00% <0.00%> (ø)
...src/megamek/client/ui/swing/DeploymentDisplay.java	0.00% <0.00%> (ø)
...mek/src/megamek/client/ui/swing/FiringDisplay.java	0.00% <0.00%> (ø)
megamek/src/megamek/client/ui/swing/MapMenu.java	0.00% <0.00%> (ø)
...k/src/megamek/client/ui/swing/MovementDisplay.java	0.00% <0.00%> (ø)
...k/src/megamek/client/ui/swing/PhysicalDisplay.java	0.00% <0.00%> (ø)
...megamek/client/ui/swing/PointblankShotDisplay.java	0.00% <0.00%> (ø)
...k/src/megamek/client/ui/swing/PrephaseDisplay.java	0.00% <0.00%> (ø)
...mek/src/megamek/client/ui/swing/ReportDisplay.java	0.00% <0.00%> (ø)
... and 6 more

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[NickAragua]

This one, we'll definitely need people to bang on before we hit the release.

[Windchild292]

I completely concur, and it is already part of the testing branch builds from last night.