Roundstart variation game rules (#24397)

* Raise `StationPostInitEvent` broadcast

* Basic variation pass handling

* standardize names + rule entities

* why does it work like that?

* add to defaults

* light break variation pass

* ent spawn entry

* move some stationevent utility functions to gamerule + add one for finding random tile on specified station

* forgot how statistics works

* powered light variation pass is good now

* station tile count function

* public method to ensure all solutions (for procedural use before mapinit)

* move gamerulesystem utility funcs to partial

* ensure all solutions before spilling in puddlesystem. for use when spilling before mapinit

* trash & puddle variation passes!

* oh yeah

* ehh lets live a little

* std

* utility for game rule check based on comp

* entprotoid the trash spawner oops

* generalize trash variation

* use added instead of started for secret rule

* random cleanup

* generic replacement variation system

* Wall rusting variation rule

* account for modifying while enumerating

* use localaabb

* fix test

* minor tweaks

* reinforced wall replacer + puddletweaker

Content.IntegrationTests/Tests/GameRules/SecretStartsTest.cs

@@ -21,7 +21,10 @@ public sealed class SecretStartsTest
 
         await server.WaitAssertion(() =>
         {
-            gameTicker.StartGameRule("Secret");
+            // this mimics roundflow:
+            // rules added, then round starts
+            gameTicker.AddGameRule("Secret");
+            gameTicker.StartGamePresetRules();
         });
 
         // Wait three ticks for any random update loops that might happen