Revert "Replace signed in user for identity.requester (#73750)" (#73962)

This reverts commit 9b9c9e83dc.

pkg/expr/transform.go

@@ -8,8 +8,8 @@ import (
 
 	"github.com/grafana/grafana-plugin-sdk-go/backend"
 
-	"github.com/grafana/grafana/pkg/services/auth/identity"
 	"github.com/grafana/grafana/pkg/services/datasources"
+	"github.com/grafana/grafana/pkg/services/user"
 )
 
 // Request is similar to plugins.DataQuery but with the Time Ranges is per Query.
@@ -18,7 +18,7 @@ type Request struct {
 	Debug   bool
 	OrgId   int64
 	Queries []Query
-	User    identity.Requester
+	User    *user.SignedInUser
 }
 
 // Query is like plugins.DataSubQuery, but with a a time range, and only the UID