feat(build): create release pipeline for runtime-metamodel

[paullatzelsperger]

What this PR changes/adds

This PR adds two things:

1. a release workflow (identical to the main EDC repo)
2. a bit of logic for the build to be able to set the version on the CLI using the -Pversion=... parameter

Why it does that

To be able to easily create release and SNAPSHOT versions

Further notes

no new code has been implemented, I merely copied the logic from the EDC repo

Linked Issue(s)

Closes #2

Checklist

• added appropriate tests?
• performed checkstyle check locally?
• added/updated copyright headers?
• documented public classes/methods?
• added/updated relevant documentation?
• assigned appropriate label? (exclude from changelog with label no-changelog)
• formatted title correctly? (take a look at the CONTRIBUTING and styleguide for details)