Alerting: Endpoints for provisioning mute timings (#49635) (#49735)

* Add validator for mute timing and make it provisionable

* Add tests to ensure prometheus validators are running and errors are propagated

* Internal API for manipulating mute timings

* Define and generate API layer

* Wire up generated code

* Implement API handlers

* Tests for golang layer

* Fix reference bug

* Fix linter and auth tests

* Resolve semantic errors and regenerate

* Remove pointless comment

* Extract out provisioning path param keys, simplify

* Expected number of paths

(cherry picked from commit 909ebcf979)

Co-authored-by: Alexander Weaver <weaver.alex.d@gmail.com>

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

@@ -1439,26 +1439,9 @@
    "type": "object",
    "x-go-package": "github.com/prometheus/alertmanager/config"
   },
-  "MuteTiming": {
-   "properties": {
-    "name": {
-     "type": "string",
-     "x-go-name": "Name"
-    },
-    "time_intervals": {
-     "items": {
-      "$ref": "#/definitions/TimeInterval"
-     },
-     "type": "array",
-     "x-go-name": "TimeIntervals"
-    }
-   },
-   "type": "object",
-   "x-go-package": "github.com/grafana/grafana/pkg/services/ngalert/api/tooling/definitions"
-  },
   "MuteTimings": {
    "items": {
-    "$ref": "#/definitions/MuteTiming"
+    "$ref": "#/definitions/MuteTimeInterval"
    },
    "type": "array",
    "x-go-package": "github.com/grafana/grafana/pkg/services/ngalert/api/tooling/definitions"
@@ -3392,7 +3375,6 @@
    "type": "array"
   },
   "gettableSilence": {
-   "description": "GettableSilence gettable silence",
    "properties": {
     "comment": {
      "description": "comment",
@@ -3444,7 +3426,9 @@
     "status",
     "updatedAt"
    ],
-   "type": "object"
+   "type": "object",
+   "x-go-name": "GettableSilence",
+   "x-go-package": "github.com/prometheus/alertmanager/api/v2/models"
   },
   "gettableSilences": {
    "items": {
@@ -3581,6 +3565,7 @@
    "x-go-package": "github.com/prometheus/alertmanager/api/v2/models"
   },
   "postableSilence": {
+   "description": "PostableSilence postable silence",
    "properties": {
     "comment": {
      "description": "comment",
@@ -3620,11 +3605,10 @@
     "matchers",
     "startsAt"
    ],
-   "type": "object",
-   "x-go-name": "PostableSilence",
-   "x-go-package": "github.com/prometheus/alertmanager/api/v2/models"
+   "type": "object"
   },
   "receiver": {
+   "description": "Receiver receiver",
    "properties": {
     "name": {
      "description": "name",
@@ -3635,9 +3619,7 @@
    "required": [
     "name"
    ],
-   "type": "object",
-   "x-go-name": "Receiver",
-   "x-go-package": "github.com/prometheus/alertmanager/api/v2/models"
+   "type": "object"
   },
   "silence": {
    "description": "Silence silence",