Feature/peer validator (#1553)

Follow up management-integrations changes

move groups to separated packages to avoid circle dependencies
save location information in Login action

management/server/integration_reference/integration_reference.go

@@ -0,0 +1,23 @@
+package integration_reference
+
+import (
+	"fmt"
+	"strings"
+)
+
+// IntegrationReference holds the reference to a particular integration
+type IntegrationReference struct {
+	ID              int
+	IntegrationType string
+}
+
+func (ir IntegrationReference) String() string {
+	return fmt.Sprintf("%s:%d", ir.IntegrationType, ir.ID)
+}
+
+func (ir IntegrationReference) CacheKey(path ...string) string {
+	if len(path) == 0 {
+		return ir.String()
+	}
+	return fmt.Sprintf("%s:%s", ir.String(), strings.Join(path, ":"))
+}