Exception madness

[RoiEXLab]

Overview

Read about https://forums.triplea-game.org/topic/1401/guests-joining-games-in-progress-crash-them/15
Hopefully this reduces the amount of thos false positive exceptions.

I believe I introduced this regression in #3447 and demonstrated how unchecked Exceptions cause bugs at a distance.

Functional Changes

Less pop-ups hopefully.

Manual Testing Performed

I verified no Exception dialog pops up when hosting locally when a user disconnects and a headless host doesn't actuall log an exception when a user disconnects

[codecov-io]

Codecov Report

Merging #5018 into master will decrease coverage by <.01%.
The diff coverage is 0%.

@@             Coverage Diff              @@
##             master    #5018      +/-   ##
============================================
- Coverage     23.95%   23.94%   -0.01%     
+ Complexity     6724     6722       -2     
============================================
  Files           998      998              
  Lines         77753    77764      +11     
  Branches      11625    11633       +8     
============================================
- Hits          18624    18621       -3     
- Misses        56984    56996      +12     
- Partials       2145     2147       +2

Impacted Files	Coverage Δ	Complexity Δ
...ine/message/unifiedmessenger/UnifiedMessenger.java	77.55% <ø> (ø)	27 <0> (ø)	⬇️
...ategy/engine/message/UnifiedInvocationHandler.java	80.95% <ø> (ø)	7 <0> (ø)	⬇️
...es/strategy/engine/message/MessengerException.java	100% <ø> (ø)	1 <0> (ø)	⬇️
...ine/framework/startup/launcher/ServerLauncher.java	0% <0%> (ø)	0 <0> (ø)	⬇️
...es/strategy/engine/player/DefaultPlayerBridge.java	0% <0%> (ø)	0 <0> (ø)	⬇️
...va/games/strategy/engine/framework/ServerGame.java	0% <0%> (ø)	0 <0> (ø)	⬇️
...trategy/engine/delegate/DefaultDelegateBridge.java	0% <0%> (ø)	0 <0> (ø)	⬇️
.../java/games/strategy/engine/GameOverException.java	0% <0%> (ø)	0 <0> (ø)	⬇️
...tegy/engine/delegate/DelegateExecutionManager.java	25% <0%> (ø)	6 <0> (ø)	⬇️
...rategy/triplea/attachments/UnitTypeComparator.java	46.15% <0%> (-7.7%)	12% <0%> (-1%)
... and 1 more

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