User settings page and admin settings page are too similar. I thinlk this will be better of using `User Settings` and `Admin Settings` as the navbar's title. Before: ![image](https://github.com/go-gitea/gitea/assets/18380374/68db06f3-918b-41bc-b4d3-522b1057eb57) ![image](https://github.com/go-gitea/gitea/assets/18380374/24f53d91-54e1-410c-ad9b-438bb2c8069f) After: ![image](https://github.com/go-gitea/gitea/assets/18380374/6600a872-d630-4ea6-a58f-d9ded7d38067) ![image](https://github.com/go-gitea/gitea/assets/18380374/501cde5d-9868-4cba-829d-ff8bafce695d)