feat(auth): add ability to regenerate access tokens (#6963)

- Add the ability to regenerate existing access tokens in the UI. This preserves the ID of the access token, but generates a new salt and token contents.
- Integration test added.
- Unit test added.
- Resolves #6880

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/6963
Reviewed-by: 0ko <0ko@noreply.codeberg.org>
Reviewed-by: Gusted <gusted@noreply.codeberg.org>
Co-authored-by: Dmitrii Sharshakov <d3dx12.xx@gmail.com>
Co-committed-by: Dmitrii Sharshakov <d3dx12.xx@gmail.com>

routers/web/web.go

@@ -586,6 +586,7 @@ func registerRoutes(m *web.Route) {
 			m.Combo("").Get(user_setting.Applications).
 				Post(web.Bind(forms.NewAccessTokenForm{}), user_setting.ApplicationsPost)
 			m.Post("/delete", user_setting.DeleteApplication)
+			m.Post("/regenerate", user_setting.RegenerateApplication)
 		})
 
 		m.Combo("/keys").Get(user_setting.Keys).