add headless chromium software release
This change includes a rewrite of the previous
component/headless-chromium, which used an outdated version of Chromium. It differs from
component/chromium in that:
- It only provides a headless shell, rather than the full Chromium browser (though this can be changed).
- It compiles from source rather than downloading a binary build.
There is also a new software release
software/headless-chromium which makes use of the updated
component/headless-chromium to expose a remote debugging port.