Mono repo -> Master (#22553)

Combines the following repositories into one:

https://github.com/mattermost/mattermost-server
https://github.com/mattermost/mattermost-webapp
https://github.com/mattermost/focalboard
https://github.com/mattermost/mattermost-plugin-playbooks

server/channels/db/migrations/mysql/000017_create_roles.up.sql

@@ -0,0 +1,61 @@
+CREATE TABLE IF NOT EXISTS Roles (
+   Id varchar(26) NOT NULL,
+   Name varchar(64) DEFAULT NULL,
+   DisplayName varchar(128) DEFAULT NULL,
+   Description text,
+   CreateAt bigint(20) DEFAULT NULL,
+   UpdateAt bigint(20) DEFAULT NULL,
+   DeleteAt bigint(20) DEFAULT NULL,
+   Permissions text,
+   SchemeManaged tinyint(1) DEFAULT NULL,
+   PRIMARY KEY (Id),
+   UNIQUE KEY Name (Name)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+
+SET @preparedStatement = (SELECT IF(
+    (
+        SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS
+        WHERE table_name = 'Roles'
+        AND table_schema = DATABASE()
+        AND column_name = 'BuiltIn'
+    ) > 0,
+    'SELECT 1',
+    'ALTER TABLE Roles ADD BuiltIn tinyint(1) DEFAULT NULL;'
+));
+
+PREPARE alterIfNotExists FROM @preparedStatement;
+EXECUTE alterIfNotExists;
+DEALLOCATE PREPARE alterIfNotExists;
+
+CREATE PROCEDURE Migrate_If_Version_Below_500 ()
+BEGIN
+DECLARE
+	CURRENT_DB_VERSION TEXT;
+	SELECT
+		Value
+	FROM
+		Systems
+	WHERE
+		Name = 'Version' INTO CURRENT_DB_VERSION;
+	IF(INET_ATON(CURRENT_DB_VERSION) < INET_ATON('5.0.0')) THEN
+		UPDATE Roles SET SchemeManaged = 0
+            WHERE Name NOT IN ('system_user', 'system_admin', 'team_user', 'team_admin', 'channel_user', 'channel_admin');
+	END IF;
+END;
+	CALL Migrate_If_Version_Below_500 ();
+	DROP PROCEDURE IF EXISTS Migrate_If_Version_Below_500;
+
+SET @preparedStatement = (SELECT IF(
+    (
+        SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS
+        WHERE table_name = 'Roles'
+        AND table_schema = DATABASE()
+        AND column_name = 'Permissions'
+    ) > 0,
+    'ALTER TABLE Roles MODIFY Permissions longtext;',
+    'SELECT 1'
+));
+
+PREPARE alterIfExists FROM @preparedStatement;
+EXECUTE alterIfExists;
+DEALLOCATE PREPARE alterIfExists;