feat(api): migrate server and node data handling, update related structures and logic

initialize/migrate/database/02106_subscribe.up.sql

@@ -0,0 +1,7 @@
+ALTER TABLE `subscribe`
+ADD COLUMN `nodes` VARCHAR(255) NOT NULL DEFAULT '' COMMENT 'Node IDs',
+ADD COLUMN `node_tags` VARCHAR(255) NOT NULL DEFAULT '' COMMENT 'Node Tags',
+DROP COLUMN `server`,
+DROP COLUMN `server_group`;
+
+DROP TABLE IF EXISTS `server_rule_group`;