Testing updated Eclipse signing service for macos

[netomi]

We want to deploy a new version of the Macos signing service of the Eclipse Foundation.

It uses the open-source tool rcodesign instead of the native codesign tool, allowing it to run in our openshift cluster.

The service is deployed at cbi-staging.eclipse.org, the rest is the same as for the current production service on cbi.eclipse.org.

There is currently still a bug in rcodesign that fails to read xar files with extended attributes, a fix has been created already (indygreg/apple-platform-rs#155). So the final installer packages with .pkg extension might fail due to that.