[Alerting]: Several modifications in alert rules (#32983)

* [Alerting]: Use common properties for all rules

* Add Labels in rules

* Fix update ruleGroup API

Return 400 Bad Request response
when the request contains a UID that does not exist

* Check permissions and return namespace id

* Apply suggestions from code review

Co-authored-by: gotjosh <josue@grafana.com>

pkg/services/ngalert/api/test-data/post-rulegroup-42.json

@@ -3,13 +3,16 @@
   "interval": "10s",
   "rules": [
     {
+      "for": "1m",
+      "annotations": {
+        "foo": "bar"
+      },
+      "labels": {
+        "label1": "val1"
+      },
       "grafana_alert": {
         "title": "prom query with SSE",
         "condition": "condition",
-        "for": 5,
-        "annotations": {
-          "foo": "bar"
-        },
         "data": [
           {
             "refId": "query",