[MM-37984] Allow Desktop App to authenticate via external providers outside of the app on supported servers (#24140)

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

* PR feedback

* Add support for mattermost-dev protocol for development use

* Update server/channels/db/migrations/postgres/000110_create_desktop_tokens.up.sql

* Fix silly typo

* Update server/channels/db/migrations/postgres/000110_create_desktop_tokens.up.sql

* Remove storage of client token, only validate it on the client

* Update migrations

* Add concurrently create index

* Remove CONCURRENTLY for now

* Fix issue with changing history

* Remove old migration

* Use idempotent statement to drop old index

* Remove reference to old table

webapp/platform/client/src/client4.ts

@@ -755,6 +755,18 @@ 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 = {