feat(web,server): external domain setting (#6146)

* feat: external domain setting

* chore: open api

* mobile: handle serverconfig-externalDomain

---------

Co-authored-by: shenlong-tanwen <139912620+shalong-tanwen@users.noreply.github.com>

server/test/e2e/server-info.e2e-spec.ts

@@ -97,6 +97,7 @@ describe(`${ServerInfoController.name} (e2e)`, () => {
         oauthButtonText: 'Login with OAuth',
         trashDays: 30,
         isInitialized: true,
+        externalDomain: '',
       });
     });
   });