Alerting: Allow administrators delete rules permanently via UI (#101974)

* add query parameter to existing APIs to control the permanent deletion of rules
* add GUID to gettable rule
* add new endpoint /ruler/grafana/api/v1/trash/rule/guid/{RuleGUID} to delete rules from trash permanently

---------

Signed-off-by: Yuri Tseretyan <yuriy.tseretyan@grafana.com>

pkg/services/ngalert/api/authorization_test.go

@@ -41,7 +41,7 @@ func TestAuthorize(t *testing.T) {
 		}
 		paths[p] = methods
 	}
-	require.Len(t, paths, 66)
+	require.Len(t, paths, 67)
 
 	ac := acmock.New()
 	api := &API{AccessControl: ac, FeatureManager: featuremgmt.WithFeatures()}