[v11.0.x] Annotations: Optimize search by tags (#93609)

Annotations: Optimize search by tags (#93547)

* Annotations: Optimize search on large number of dashboards

* refactor

* fix batch size

* Return early if no annotations found

* revert go.mod

* return nil in case of error

* Move default limit to the API package

* fix empty access control filter

* Set default limit to 100

* optimize query when number of annotations is less than limit

* Update pkg/services/annotations/annotationsimpl/annotations.go

Co-authored-by: Ieva <ieva.vasiljeva@grafana.com>

* remove limit from store since it's set in API

* set default limit in Find method (do not break tests)

* Only add limit to the query if it's set

* use limit trick for all searches without dashboard filter

* set default page if not provided

---------

Co-authored-by: Ieva <ieva.vasiljeva@grafana.com>
(cherry picked from commit 5e713673e1)

Co-authored-by: Alexander Zobnin <alexanderzobnin@gmail.com>

pkg/services/annotations/models.go

@@ -21,6 +21,7 @@ type ItemQuery struct {
 	SignedInUser identity.Requester
 
 	Limit int64 `json:"limit"`
+	Page  int64
 }
 
 // TagsQuery is the query for a tags search.