Features: Add aplha feature toggle for authn service (#59469)

* Features: Add aplha feature toggle for authn service

* AuthN: Add service boilerplate

* Set authnz-team as codeowners of authn service

pkg/services/authn/authnimpl/service.go

@@ -0,0 +1,8 @@
+package authnimpl
+
+import "github.com/grafana/grafana/pkg/services/authn"
+
+var _ authn.Service = new(Service)
+
+type Service struct {
+}