feat(user): add endpoint and logic for updating user rules

initialize/migrate/database/02120_user_rules.down.sql

@@ -0,0 +1,2 @@
+ALTER TABLE `user`
+DROP COLUMN IF EXISTS `rules`;

initialize/migrate/database/02120_user_rules.up.sql

@@ -0,0 +1,4 @@
+ALTER TABLE `user`
+    ADD COLUMN `rules` TEXT NULL
+  COMMENT 'User rules for subscription'
+  AFTER `created_at`;