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/tests/api/alerting/api_provisioning_test.go

@@ -69,7 +69,7 @@ func createRuleWithNotificationSettings(t *testing.T, client apiClient, folder s
 			},
 		},
 	}
-	resp, status, _ := client.PostRulesGroupWithStatus(t, folder, &rules)
+	resp, status, _ := client.PostRulesGroupWithStatus(t, folder, &rules, false)
 	assert.Equal(t, http.StatusAccepted, status)
 	require.Len(t, resp.Created, 1)
 	return rules, resp.Created[0]