Draft: Adding options to have a sidecar container in renderer to serve pre-collected static files

This creates a setup for collecting and serving static files.

Changes:

• chart:
  • values:
    • Add config structure in registrar.config.static to configure static files handling, enabled by default
    • Removed "COLLECT_STATIC" env variable, to be replaced with the config
  • Add sidecar container in deployment to handle static files
• image: updated to eoxserver 1.2.11 to allow setting of STATIC_ROOT and STATIC_URL via env vars