Alerting: Support for optimistic concurrency in priovisioning Tempate API (#91195)

* support optimistic concurrency in template service

* update request handler to get version from query parameter

* return not found if a new template is set with version

* update PUT api to set version

* update documentation + for mute timings

---------

Co-authored-by: brendamuir <100768211+brendamuir@users.noreply.github.com>

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

@@ -2264,6 +2264,9 @@
     },
     "template": {
      "type": "string"
+    },
+    "version": {
+     "type": "string"
     }
    },
    "type": "object"
@@ -2272,6 +2275,9 @@
    "properties": {
     "template": {
      "type": "string"
+    },
+    "version": {
+     "type": "string"
     }
    },
    "type": "object"
@@ -6183,16 +6189,28 @@
     "operationId": "RouteDeleteTemplate",
     "parameters": [
      {
-      "description": "Template Name",
+      "description": "Template name",
       "in": "path",
       "name": "name",
       "required": true,
       "type": "string"
+     },
+     {
+      "description": "Version of template to use for optimistic concurrency. Leave empty to disable validation",
+      "in": "query",
+      "name": "version",
+      "type": "string"
      }
     ],
     "responses": {
      "204": {
       "description": " The template was deleted successfully."
+     },
+     "409": {
+      "description": "GenericPublicError",
+      "schema": {
+       "$ref": "#/definitions/GenericPublicError"
+      }
      }
     },
     "summary": "Delete a template.",
@@ -6265,6 +6283,12 @@
       "schema": {
        "$ref": "#/definitions/ValidationError"
       }
+     },
+     "409": {
+      "description": "GenericPublicError",
+      "schema": {
+       "$ref": "#/definitions/GenericPublicError"
+      }
      }
     },
     "summary": "Updates an existing notification template.",