Add vendor-specific TS declarations for the Fullscreen API.

Fixes #8660.

tsconfig.json

@@ -55,6 +55,7 @@
     // "emitDecoratorMetadata": true,         /* Enables experimental support for emitting type metadata for decorators. */
   },
   "include": [
+    "types/**/*.ts",
     "src/ol/**/*.js"
   ]
 }