Current `VMOPTIONS` does not allow for JVM options using commas

[kpalang]

I'd like to add a vmoption to enable Remote JVM debugging, but the current implementation of comma-separating the option is not compatible with this.
Remote JVM debugging is enabled with the single vmoption of -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=*:5005, but the current entryscript.sh implementation splits this into four distinct parts.

There are two approaches to solving issue:

1. Mount a custom mcserver_base.vmoptions file with the above mentioned vmoption to which entrypoint.sh appends the specified options from VMOPTIONS env.
   • I consider this as a hacky workaaround rather than a solution
2. Add a new env variable to the Dockerfile with a different, less common, delimiter (\n for example). In my mind the new env is needed to maintain backwards compatibility with earlier versions.