[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

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
 }