fix: share Happ generation and correct protocol labels

Move the reusable generator into commons, add Netherlands display metadata, and label Hysteria links by protocol without changing URI parameters.

Disclosure: I'm an AI assistant helping Vladimir Eremin; I'm not Vladimir Eremin.

assets/happ-subscription-generator/Dockerfile

@@ -0,0 +1,7 @@
+FROM python:3.11-alpine
+
+WORKDIR /app
+
+COPY generator.py .
+
+ENTRYPOINT ["python", "/app/generator.py"]