Alerting: Rule Modify Export APIs (#75322)

* extend RuleStore interface to get namespace by UID
* add new export API endpoints
* implement request handlers
* update authorization and wire handlers to paths
* add folder error matchers to errorToResponse
* add tests for export methods

pkg/services/ngalert/api/tooling/definitions/cortex-ruler.go

@@ -19,6 +19,18 @@ import (
 //       202: NamespaceConfigResponse
 //
 
+// swagger:route Get /api/ruler/grafana/api/v1/export/rules ruler RouteGetRulesForExport
+//
+// List rules in provisioning format
+//
+//     Consumes:
+//     - application/json
+//     - application/yaml
+//
+//     Responses:
+//       200: AlertingFileExport
+//       404: description: Not found.
+
 // swagger:route Get /api/ruler/{DatasourceUID}/api/v1/rules ruler RouteGetRulesConfig
 //
 // List rule groups
@@ -42,6 +54,18 @@ import (
 //       202: Ack
 //
 
+// swagger:route POST /api/ruler/grafana/api/v1/rules/{Namespace}/export ruler RoutePostRulesGroupForExport
+//
+// Converts submitted rule group to provisioning format
+//
+//     Consumes:
+//     - application/json
+//     - application/yaml
+//
+//     Responses:
+//       200: AlertingFileExport
+//       404: description: Not found.
+
 // swagger:route POST /api/ruler/{DatasourceUID}/api/v1/rules/{Namespace} ruler RoutePostNameRulesConfig
 //
 // Creates or updates a rule group
@@ -126,7 +150,7 @@ import (
 //       202: Ack
 //       404: NotFound
 
-// swagger:parameters RoutePostNameRulesConfig RoutePostNameGrafanaRulesConfig
+// swagger:parameters RoutePostNameRulesConfig RoutePostNameGrafanaRulesConfig RoutePostRulesGroupForExport
 type NamespaceConfig struct {
 	// in:path
 	Namespace string

pkg/services/ngalert/api/tooling/definitions/provisioning.go

@@ -9,7 +9,7 @@ type AlertingFileExport struct {
 	Policies      []NotificationPolicyExport `json:"policies,omitempty" yaml:"policies,omitempty"`
 }
 
-// swagger:parameters RouteGetAlertRuleGroupExport RouteGetAlertRuleExport RouteGetContactpointsExport RouteGetContactpointExport
+// swagger:parameters RouteGetAlertRuleGroupExport RouteGetAlertRuleExport RouteGetContactpointsExport RouteGetContactpointExport RoutePostRulesGroupForExport
 type ExportQueryParams struct {
 	// Whether to initiate a download of the file or not.
 	// in: query

pkg/services/ngalert/api/tooling/definitions/provisioning_alert_rules.go

@@ -71,7 +71,7 @@ import (
 //     Responses:
 //       204: description: The alert rule was deleted successfully.
 
-// swagger:parameters RouteGetAlertRulesExport
+// swagger:parameters RouteGetAlertRulesExport RouteGetRulesForExport
 type AlertRulesExportParameters struct {
 	ExportQueryParams
 	// UIDs of folders from which to export rules