Small refactor of URLParams stuff

Splits out the room locartion parsing from everything else to avoid
one function that fills out different parts of its return struct
depending on its args.

src/widget.ts

@@ -109,7 +109,7 @@ export const widget: WidgetHelpers | null = (() => {
         baseUrl,
         e2eEnabled,
         allowIceFallback,
-      } = getUrlParams(true);
+      } = getUrlParams();
       if (!roomId) throw new Error("Room ID must be supplied");
       if (!userId) throw new Error("User ID must be supplied");
       if (!deviceId) throw new Error("Device ID must be supplied");