Alerting: Add endpoint for querying state history (#62166)

* Define endpoint and generate

* Wire up and register endpoint

* Cleanup, define authorization

* Forgot the leading slash

* Wire up query and SignedInUser

* Wire up timerange query params

* Add todo for label queries

* Drop comment

* Update path to rules subtree

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

@@ -0,0 +1,17 @@
+package definitions
+
+import "github.com/grafana/grafana-plugin-sdk-go/data"
+
+// swagger:route GET /api/v1/rules/history history RouteGetStateHistory
+//
+// Query state history.
+//
+//     Produces:
+//     - application/json
+//
+//     Responses:
+//       200: StateHistory
+
+type StateHistory struct {
+	Results *data.Frame `json:"results"`
+}