Move m.file thumbnail_url to be inside info to match m.video

event-schemas/schema/m.room.message#m.file

@@ -20,12 +20,6 @@ properties:
           size:
             description: The size of the file in bytes.
             type: integer
-        title: FileInfo
-        type: object
-      msgtype:
-        enum:
-          - m.file
-        type: string
           thumbnail_info:
             allOf:
               - $ref: core-event-schema/msgtype_infos/image_info.yaml
@@ -35,6 +29,12 @@ properties:
           thumbnail_url:
             description: The URL to the thumbnail of the file.
             type: string
+        title: FileInfo
+        type: object
+      msgtype:
+        enum:
+          - m.file
+        type: string
       url:
         description: The URL to the file.
         type: string