[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/public/model/user.go

@@ -62,6 +62,8 @@ const (
 	UserLocaleMaxLength   = 5
 	UserTimezoneMaxRunes  = 256
 	UserRolesMaxLength    = 256
+
+	DesktopTokenTTL = time.Minute * 3
 )
 
 //msgp:tuple User