Fix join-point reload cache crash

[NemuruYama]

Alternative fix for the join-point reload crash described in #935.

Fixes a crash while creating a join-point snapshot during multiplayer reload. The old reload cache copied internal world/grid state across reload boundaries, which could leave the freshly loaded WorldGrid in an invalid state and throw from CacheForReloading during World.ExposeData.

The fix removes unsafe cache restoration for reloads and replaces it with a narrower join-point reload optimization: skip the faction-restore map drawer rebuild while the snapshot is being created, then regenerate map drawers once after the snapshot is complete.

I have never had this on the steam version, but I couldn't get the local dev branch to work untill I removed the caching.
I tried to add back some optimisations.

Mod List:

- zetrith.prepatcher
- nemuruyama.disablesteammods
- ludeon.rimworld
- ludeon.rimworld.royalty
- ludeon.rimworld.ideology
- ludeon.rimworld.biotech
- ludeon.rimworld.anomaly
- ludeon.rimworld.odyssey
- rwmt.multiplayer

SaveableFromNode exception: System.Reflection.TargetInvocationException
System.NullReferenceException: Object reference not set to an instance of an object.
   at Multiplayer.Client.WorldGridCachePatch.Prefix (...)
   in Multiplayer/Saving/CacheForReloading.cs:76
   at RimWorld.Planet.WorldGrid..ctor_Patch1(...)

Exception from long event: System.NullReferenceException: Object reference not set to an instance of an object.
  at Multiplayer.Client.WorldGridCachePatch.Prefix (
      RimWorld.Planet.WorldGrid __instance,
      System.Int32& ___cachedTraversalDistance,
      System.Int32& ___cachedTraversalDistanceForStart,
      System.Int32& ___cachedTraversalDistanceForEnd
  ) [0x00036] in Multiplayer/Saving/CacheForReloading.cs:76
  at RimWorld.Planet.GameSetupStep_Grids.GenerateFresh ()
  at RimWorld.Planet.WorldGenerator.GenerateWithoutWorldData (System.String seedString)
  at RimWorld.Planet.World.ExposeData ()
  at Verse.Game.LoadGame_Patch3(Verse.Game)
  at Multiplayer.Client.LoadPatch.Prefix () in Multiplayer/Saving/LoadPatch.cs:27
  at Verse.SavedGameLoaderNow.LoadGameFromSaveFileNow_Patch1(string)
  at Multiplayer.Client.SaveLoad.LoadInMainThread (...) in Multiplayer/Saving/SaveLoad.cs:135
  at Multiplayer.Client.SaveLoad.SaveAndReload (System.Boolean cache) in Multiplayer/Saving/SaveLoad.cs:86
  at Multiplayer.Client.AsyncTime.AsyncWorldTimeComp.CreateJoinPointAndSendIfHost ()
      in Multiplayer/AsyncTime/AsyncWorldTimeComp.cs:279

Random state stack is not empty. There were more calls to PushState than PopState. Fixing.

Exception in UIRootUpdate: System.NullReferenceException
  at RimWorld.UIRoot_Play.UIRootUpdate ()

Root level exception in Update(): System.NullReferenceException
  at RimWorld.Planet.WorldRendererUtility.get_CurrentWorldRenderMode_Patch1()
  at RimWorld.Planet.WorldRendererUtility.get_WorldSelected ()
  at Multiplayer.Client.SetMapTimeForUI.Prefix (...)

[notfood]

Can you check the test? It seems to be failing.

[NemuruYama]

Can you check the test? It seems to be failing.

They are passing locally.
It is because I made some net48 tests that honestly don't add enough to change the CI workflow.
So I removed them.