Alerting: Update provisioning to validate user-defined UID on create (#73793)

* add ValidateUID to util
* provisioning to validate UID on rule creation

---------

Co-authored-by: brendamuir <100768211+brendamuir@users.noreply.github.com>
Co-authored-by: Alexander Weaver <weaver.alex.d@gmail.com>

pkg/services/ngalert/api/tooling/api.json

@@ -2663,6 +2663,9 @@
      "type": "string"
     },
     "uid": {
+     "maxLength": 40,
+     "minLength": 1,
+     "pattern": "^[a-zA-Z0-9-_]+$",
      "type": "string"
     },
     "updated": {