[MM-37984] Allow Desktop App to authenticate via external providers outside of the app on supported servers (#23795)

* WIP

* Add rate limiting for desktop token API

* Missing mocks

* Style fixes

* Update snapshots

* Maybe use an actual redirect link :P

* Refactoring for tests

* Add tests for server

* Fix lint issue

* Fix tests

* Fix lint

* Add front-end screen component

* Component logic

* Style changes

* Quick style fix

* Lint fixes

* Initial PR feedback

* Enable logging into the browser as well when completing the login process

* Refactor to push more logic to the other component

* Remove unnecessary helper code

* Fix i18n

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

webapp/platform/client/src/client4.ts

@@ -756,6 +756,18 @@ export default class Client4 {
         return profile;
     };
 
+    loginWithDesktopToken = async (token: string) => {
+        const body: any = {
+            token,
+            deviceId: '',
+        };
+
+        return await this.doFetch<UserProfile>(
+            `${this.getUsersRoute()}/login/desktop_token`,
+            {method: 'post', body: JSON.stringify(body)},
+        );
+    };
+
     loginById = (id: string, password: string, token = '') => {
         this.trackEvent('api', 'api_users_login');
         const body: any = {