[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>

server/channels/store/retrylayer/retrylayer_test.go

@@ -59,6 +59,7 @@ func genStore() *mocks.Store {
 	mock.On("PostAcknowledgement").Return(&mocks.PostAcknowledgementStore{})
 	mock.On("PostPersistentNotification").Return(&mocks.PostPersistentNotificationStore{})
 	mock.On("TrueUpReview").Return(&mocks.TrueUpReviewStore{})
+	mock.On("DesktopTokens").Return(&mocks.DesktopTokensStore{})
 	return mock
 }