Add PythonValidator

This validator is used by the Java printer at development time and by the Java parser facade to validate the LST model type constraints.

Author: knutwannheden

rewrite-python-remote/src/main/java/org/openrewrite/python/remote/PythonSenderReceiverProvider.java

@@ -20,6 +20,7 @@
 import org.openrewrite.remote.Receiver;
 import org.openrewrite.remote.Sender;
 import org.openrewrite.remote.SenderReceiverProvider;
+import org.openrewrite.remote.Validator;
 
 @AutoService(SenderReceiverProvider.class)
 public class PythonSenderReceiverProvider implements SenderReceiverProvider<Py> {
@@ -37,4 +38,9 @@ public Sender<Py> newSender() {
     public Receiver<Py> newReceiver() {
         return new PythonReceiver();
     }
+
+    @Override
+    public Validator newValidator() {
+        return Validator.fromVisitor(new PythonValidator<>());
+    }
 }