Alerting: Rule version history API (#99041)

* implement store method to read rule versions

* implement request handler

* declare a new endpoint

* fix fake to return correct response

* add tests

* add integration tests

* rename history to versions

* apply diff from swagger CI step

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

---------

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

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

@@ -20,6 +20,18 @@ import (
 //       403: ForbiddenError
 //       404: description: Not found.
 
+// swagger:route Get /ruler/grafana/api/v1/rule/{RuleUID}/versions ruler RouteGetRuleVersionsByUID
+//
+// Get rule versions by UID
+//
+//     Produces:
+//     - application/json
+//
+//     Responses:
+//       202: GettableRuleVersions
+//       403: ForbiddenError
+//       404: description: Not found.
+
 // swagger:route Get /ruler/grafana/api/v1/rules ruler RouteGetGrafanaRulesConfig
 //
 // List rule groups
@@ -218,7 +230,7 @@ type PathGetRulesParams struct {
 	PanelID int64
 }
 
-// swagger:parameters RouteGetRuleByUID
+// swagger:parameters RouteGetRuleByUID RouteGetRuleVersionsByUID
 type PathGetRuleByUIDParams struct {
 	// in: path
 	RuleUID string
@@ -290,6 +302,9 @@ func (c *PostableRuleGroupConfig) validate() error {
 	return nil
 }
 
+// swagger:model
+type GettableRuleVersions []GettableExtendedRuleNode
+
 // swagger:model
 type GettableRuleGroupConfig struct {
 	Name     string                     `yaml:"name" json:"name"`