OAuth applications can already have multiple redirect URIs if created/edited over API. This change allows for setting multiple redirect URIs through the UI as a comma-separated list (e. g. `https://example.org/redirect,https://redirect.example.org`) <details> <summary>Screenshots</summary> ![Bildschirmfoto vom 2023-06-04 17-14-40](https://github.com/go-gitea/gitea/assets/47871822/2206dc32-e7e4-4953-9ecb-e098890b3f54) ![Bildschirmfoto vom 2023-06-04 17-14-50](https://github.com/go-gitea/gitea/assets/47871822/cd97c73c-9310-44ee-a83a-b927a1ef94da) </details> Closes #25068