Add optional Python/JEP support to simple Docker image

[moqui-industrial]

Summary

This PR adds optional Python and JEP (Java Embedded Python) support to the simple Docker image build. The build is completely opt-in and auto-detected, introducing zero modifications to the core framework's build.gradle.

All opinionated Swarm/stack deployment configurations from the previous PR attempt have been removed, as they will be moved to a separate moqui-deploy component.

Changes

1. Dockerfile: Added a WITH_JEP build argument (default false). When true, it installs Python 3 dependencies, creates a virtual environment inside the runtime directory, and pre-installs numpy and jep.
2. docker-build.sh: Auto-detects if the moqui-jep component is present under runtime/component/. If detected, it automatically passes --build-arg WITH_JEP=true to the build command.
3. docker-entrypoint.sh: Added a custom entrypoint script that dynamically resolves the location of the JEP native library (libjep.so) inside the virtualenv and starts the JVM with the required -Djep.lib and -Djep_site_pkgs system properties.

This keeps all JEP configurations completely isolated inside the moqui-jep component and ensures the Docker build remains clean and standard when JEP is not in use.