Refactor map loading & saving (#34020)

Resources/Maps/Shuttles/emergency_relic.yml

@@ -16,26 +16,11 @@ tilemap:
 entities:
 - proto: ""
   entities:
-  - uid: 1
-    components:
-    - type: MetaData
-      name: Map Entity
-    - type: Transform
-    - type: Map
-      mapPaused: True
-    - type: PhysicsMap
-    - type: GridTree
-    - type: MovedGrids
-    - type: Broadphase
-    - type: OccluderTree
-    - type: LoadedMap
   - uid: 2
     components:
     - type: MetaData
       name: grid
     - type: Transform
-      pos: -7.6484375,2.8046875
-      parent: 1
     - type: MapGrid
       chunks:
         0,0:

Resources/Prototypes/GameRules/events.yml

@@ -454,7 +454,7 @@
     duration: 1
   - type: RuleGrids
   - type: LoadMapRule
-    mapPath: /Maps/Shuttles/ShuttleEvent/striker.yml
+    gridPath: /Maps/Shuttles/ShuttleEvent/striker.yml
   - type: NukeopsRule
     roundEndBehavior: Nothing
   - type: AntagSelection

Resources/Prototypes/Maps/centcomm.yml

@@ -1,5 +1,6 @@
 - type: gameMap
   id: CentComm
+  isGrid: true # Did you know that centcomm is the only "game map" that isn't actually a map? Send help.
   mapName: 'Central Command'
   mapPath: /Maps/centcomm.yml
   minPlayers: 10