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/comments/sql_storage_test.go

@@ -5,15 +5,15 @@ import (
 	"strconv"
 	"testing"
 
+	"github.com/grafana/grafana/pkg/infra/db"
 	"github.com/grafana/grafana/pkg/services/comments/commentmodel"
-	"github.com/grafana/grafana/pkg/services/sqlstore"
 
 	"github.com/stretchr/testify/require"
 )
 
 func createSqlStorage(t *testing.T) Storage {
 	t.Helper()
-	sqlStore := sqlstore.InitTestDB(t)
+	sqlStore := db.InitTestDB(t)
 	return &sqlStorage{
 		sql: sqlStore,
 	}