Fix switch warnings (#4013)

* Fix switch warnings
  * Fix a variety of -Wswitch and -Wswitch-enum warnings
  * Remove unneeded -Wno-error flags

* Reorganise some eMonsterType switches
  * Alpha sort eMonsterType cases in WriteMobMetadata
    and in cNBTChunkSerializer::AddMonsterEntity
  * List all mob types in protocol 1.12 and NBTChunkSerializer

* cStructGenTrees::GetNumTrees: remove switch default

* cWSSAnvil::LoadOldMinecartFromNBT: Log unhandled minecart type

src/Generating/FinishGen.cpp

@@ -586,9 +586,11 @@ bool cFinishGenVines::IsJungleVariant(EMCSBiome a_Biome)
 		{
 			return true;
 		}
+		default:
+		{
+			return false;
+		}
 	}
-
-	return false;
 }