Fix 3880 cannot refit clan mechs due to renames

[Sleet01]

This should fix both Clan configuration changes and custom refits.
Edit: also fixes an NPE when all Techs are occupied and the user wants to start a Refit.

The problem is obviously the requirement to include the Clan unit name in parentheses when doing Clan unit lookups.

I am open to refining this fix further, such as:

• Adding a Clan-aware lookup within the unit cache
• Further refining the new utility function so that it can return the filtered list of alternate configurations required by the Refit/Configuration... chooser
• Figuring out a faster fuzzy search that will return all matching units (possibly by changing the namesMap to a BTree or something)
• Adding new tests to verify more Clan configs work correctly with Refits,

but this fix works now, and I don't have time to do any more for probably a week.

Testing:

• Verified fixed issues reported in [0.49.18] MekHQ mech customisation in Mek Lab fails on Clan mechs #3880
• Ran all three projects' unit tests
• Added new unit test covering Masakari A->B conversion (this doesn't test the names issue, but was a hole in our testing)

Close #3880

[Sleet01]

Converted to draft due to CI failures. Will clean up in a bit.

[Sleet01]

Tests broken after pulling latest Planetary Conditions code; should be fixed by /pull/3834

[SJuliez]

Thanks for dealing with the clan name thing.

[Sleet01]

Thanks for dealing with the clan name thing.

There may be some other spots where we'll want to replace getChassis() with getFullChassis() but I figure that can be a separate PR.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 18 lines in your changes are missing coverage. Please review.

Project coverage is 10.69%. Comparing base (d1d1d9a) to head (61095a9).
Report is 56 commits behind head on master.

Files	Patch %	Lines
MekHQ/src/mekhq/Utilities.java	0.00%	10 Missing ⚠️
MekHQ/src/mekhq/gui/dialog/ChooseRefitDialog.java	0.00%	6 Missing ⚠️
MekHQ/src/mekhq/campaign/parts/Refit.java	0.00%	1 Missing ⚠️
MekHQ/src/mekhq/gui/CampaignGUI.java	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #3899      +/-   ##
============================================
+ Coverage     10.64%   10.69%   +0.04%     
- Complexity     5487     5528      +41     
============================================
  Files           834      834              
  Lines        113857   113866       +9     
  Branches      17193    17196       +3     
============================================
+ Hits          12121    12176      +55     
+ Misses       100526   100462      -64     
- Partials       1210     1228      +18     

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