Alerting: extend rules export API to filter by folder and group (#74423)

update endpoint `GET /api/v1/provisioning/alert-rules/export` to accept query parameters `folderUid` and `group`

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

@@ -4066,7 +4066,6 @@
    "type": "object"
   },
   "alertGroup": {
-   "description": "AlertGroup alert group",
    "properties": {
     "alerts": {
      "description": "alerts",
@@ -4195,7 +4194,6 @@
    "type": "object"
   },
   "gettableAlert": {
-   "description": "GettableAlert gettable alert",
    "properties": {
     "annotations": {
      "$ref": "#/definitions/labelSet"
@@ -4251,14 +4249,12 @@
    "type": "object"
   },
   "gettableAlerts": {
-   "description": "GettableAlerts gettable alerts",
    "items": {
     "$ref": "#/definitions/gettableAlert"
    },
    "type": "array"
   },
   "gettableSilence": {
-   "description": "GettableSilence gettable silence",
    "properties": {
     "comment": {
      "description": "comment",
@@ -4307,7 +4303,6 @@
    "type": "object"
   },
   "gettableSilences": {
-   "description": "GettableSilences gettable silences",
    "items": {
     "$ref": "#/definitions/gettableSilence"
    },
@@ -6469,6 +6464,18 @@
       "in": "query",
       "name": "format",
       "type": "string"
+     },
+     {
+      "description": "UID of folder from which export rules",
+      "in": "query",
+      "name": "folderUid",
+      "type": "string"
+     },
+     {
+      "description": "Name of group of rules to export. Must be specified only together with folder UID",
+      "in": "query",
+      "name": "group",
+      "type": "string"
      }
     ],
     "responses": {