[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/mysql/000112_rework_desktop_tokens.down.sql

@@ -0,0 +1,16 @@
+SET @preparedStatement = (SELECT IF(
+    (
+        SELECT COUNT(*) FROM INFORMATION_SCHEMA.STATISTICS
+        WHERE table_name = 'DesktopTokens'
+        AND table_schema = DATABASE()
+        AND index_name = 'idx_desktoptokens_createat'
+    ) > 0,
+    'DROP INDEX idx_desktoptokens_createat ON DesktopTokens;',
+    'SELECT 1'
+));
+
+PREPARE removeIndexIfExists FROM @preparedStatement;
+EXECUTE removeIndexIfExists;
+DEALLOCATE PREPARE removeIndexIfExists;
+
+DROP TABLE IF EXISTS DesktopTokens;

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

@@ -0,0 +1,38 @@
+SET @preparedStatement = (SELECT IF(
+    (
+        SELECT COUNT(*) FROM INFORMATION_SCHEMA.STATISTICS
+        WHERE table_name = 'DesktopTokens'
+        AND table_schema = DATABASE()
+        AND index_name = 'idx_desktoptokens_createat'
+    ) > 0,
+    'DROP INDEX idx_desktoptokens_createat ON DesktopTokens;',
+    'SELECT 1'
+));
+
+PREPARE removeIndexIfExists FROM @preparedStatement;
+EXECUTE removeIndexIfExists;
+DEALLOCATE PREPARE removeIndexIfExists;
+
+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)
+);
+
+SET @preparedStatement = (SELECT IF(
+    (
+        SELECT COUNT(*) FROM INFORMATION_SCHEMA.STATISTICS
+        WHERE table_name = 'DesktopTokens'
+        AND table_schema = DATABASE()
+        AND index_name = 'idx_desktoptokens_token_createat'
+    ) > 0,
+    'SELECT 1',
+    'CREATE INDEX idx_desktoptokens_token_createat ON DesktopTokens(Token, CreateAt);'
+));
+
+PREPARE createIndexIfNotExists FROM @preparedStatement;
+EXECUTE createIndexIfNotExists;
+DEALLOCATE PREPARE createIndexIfNotExists;