[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/db/migrations/postgres/000112_rework_desktop_tokens.down.sql

@@ -0,0 +1,2 @@
+DROP INDEX IF EXISTS idx_desktoptokens_token_createat;
+DROP TABLE IF EXISTS desktoptokens;

server/channels/db/migrations/postgres/000112_rework_desktop_tokens.up.sql

@@ -0,0 +1,11 @@
+DROP INDEX IF EXISTS idx_desktoptokens_createat;
+DROP TABLE IF EXISTS desktoptokens;
+
+CREATE TABLE IF NOT EXISTS desktoptokens (
+    token VARCHAR(64) NOT NULL,
+    createat BIGINT NOT NULL,
+    userid VARCHAR(26) NOT NULL,    
+    PRIMARY KEY (token)
+);
+
+CREATE INDEX IF NOT EXISTS idx_desktoptokens_token_createat ON desktoptokens(token, createat)