chore: remove sqlstore & mockstore dependencies from (most) packages (#57087)

* chore: add alias for InitTestDB and Session

Adds an alias for the sqlstore InitTestDB and Session, and updates tests using these to reduce dependencies on the sqlstore.Store.

* next pass of removing sqlstore imports
* last little bit
* remove mockstore where possible

pkg/services/annotations/annotationsimpl/annotations.go

@@ -3,9 +3,9 @@ package annotationsimpl
 import (
 	"context"
 
+	"github.com/grafana/grafana/pkg/infra/db"
 	"github.com/grafana/grafana/pkg/infra/log"
 	"github.com/grafana/grafana/pkg/services/annotations"
-	"github.com/grafana/grafana/pkg/services/sqlstore/db"
 	"github.com/grafana/grafana/pkg/services/tag"
 	"github.com/grafana/grafana/pkg/setting"
 )