Mirror resprite (#37899)

* mirror resprite, add snapgridcenter

* antique mirror

* swap default mirror; antique-mirror renamed back to mirror, new mirror renamed rectangle-mirror, changed RSI underscore to regular dash for consistency

Resources/Prototypes/Entities/Structures/Wallmounts/mirror.yml

@@ -2,6 +2,8 @@
   id: Mirror
   name: mirror
   description: 'Mirror mirror on the wall , who''s the most robust of them all?'
+  placement:
+    mode: SnapgridCenter
   components:
   - type: WallMount
   - type: Sprite
@@ -24,3 +26,13 @@
     interfaces:
       enum.MagicMirrorUiKey.Key:
         type: MagicMirrorBoundUserInterface
+
+- type: entity
+  parent: Mirror
+  id: MirrorModern
+  name: mirror
+  suffix: rectangle
+  components:
+  - type: Sprite
+    sprite: Structures/Wallmounts/mirror.rsi
+    state: rectangle-mirror