Alerting: Persist annotations from multidimensional rules in batches (#56575)

* Reduce piecemeal state fields

* Read data directly off state instead of rule

* Unify state and context into single struct

* Expose contextual information to layer above setNextState

* Work in terms of ContextualState and call historian in batches

* Call annotations service in batches

* Export format state and reason and remove workaround in unrelated test package

* Add new method to annotation service for batch inserting

* Fix loop variable aliasing bug caught by linter, didn't change behavior

* Incl timerange on annotation tests

* Insert one at a time if tags are present

* Point to rule from ContextualState rather than copy fields

* Build annotations and copy data prior to starting goroutine

* Rename to StateTransition

* Use new bulk-insert utility

* Remove rule from StateTransition and pass in directly to historian

* Simplify annotations logic since we have only one rule

* Fix logs and context, nilcheck, simplify method name

* Regenerate mock

pkg/services/annotations/annotations.go

@@ -16,6 +16,7 @@ var (
 //go:generate mockery --name Repository --structname FakeAnnotationsRepo --inpackage --filename annotations_repository_mock.go
 type Repository interface {
 	Save(ctx context.Context, item *Item) error
+	SaveMany(ctx context.Context, items []Item) error
 	Update(ctx context.Context, item *Item) error
 	Find(ctx context.Context, query *ItemQuery) ([]*ItemDTO, error)
 	Delete(ctx context.Context, params *DeleteParams) error