adding github eoxc/prism/ repository as client/ with its complete history (originally coming from github eoxc/mundi)
built js file now named vsclient.js instead of prism.js
two stage build for production using node for building library and lightweight nginx for serving static files
one stage build for development - docker build -f client/Dockerfile.dev -t registry.gitlab.eox.at/esa/prism/vs/pvs_client:dev client/ utilizing node and webpack dev-server allowing hot-reload in running dev stack
update bumpversion script to also bump client package.json and package-lock.json
install corsheaders django plugin and configure it for DEV=true env - added to dev renderer®istrar services in compose files (we do not know which one will do the configuration)
