Move server-side relay auth out of shared and drop the unused validator

relay/auth/allow/allow_all.go

@@ -0,0 +1,10 @@
+package allow
+
+// Auth is a Validator that allows all connections.
+// Used this for testing purposes only.
+type Auth struct {
+}
+
+func (a *Auth) Validate(any) error {
+	return nil
+}