New event: Approaching unknown shuttle (#24490)

* setup codebase

* Add first shuttle

* tak

* sync striker

* sync 2

* pipipi

* Preloaded roundstart shuttles!

* Make it abstract "PreloaderGrid" not "PreloaderShuttle"

* to do

* added china cuisin shuttle

* fixes

* add disaster evacpod

* remove enemy

* final shuttles

* weight 5 -> 10

* move data to component

* remove autotrailer touching

* doc, respath

* fix frozen positioning

* fixes + cvar

* finally

* fix evacpod

* remove blacklistrules

* remove `UnknownShuttleSpawnRule`, refactor `LoadMapRule` to support preloaded grids

* use tryload

* cleanup

* fixes

* use preloadedgrid for loneops

* weight unknown shuttles differently (preliminal)

* leftover

* cleanup and raffling

* partial review

* singleton gridpreloader no station coupling

* fix grid atmoses

* `roleLoadout` support for `LoadoutComponent`, fix missing gear

* weighting changes

* init logic fix

---------

Co-authored-by: Kara <lunarautomaton6@gmail.com>

Content.Shared/CCVar/CCVars.cs

@@ -1375,6 +1375,12 @@ namespace Content.Shared.CCVar
         public static readonly CVarDef<bool> GridFill =
             CVarDef.Create("shuttle.grid_fill", true, CVar.SERVERONLY);
 
+        /// <summary>
+        /// Whether to automatically preloading grids by GridPreloaderSystem
+        /// </summary>
+        public static readonly CVarDef<bool> PreloadGrids =
+            CVarDef.Create("shuttle.preload_grids", true, CVar.SERVERONLY);
+
         /*
          * Emergency
          */