Adapt to use local maven build option in GitHub actions

[JanWittler]

Adapts the GitHub actions to use the local Maven builds.
Closes #510

As part of this PR, the option to execute builds with local references should be documented in the Wiki.

⚠️ Requires Vitruv-Domains#115 and Vitruv-Applications#188 to be merged first ⚠️

[HeikoKlare]

👍 Thanks!

[JanWittler]

I could need some help correctly configuring the GitHub actions. It now works somehow but as one can see I have to escape the argument for building the domain but not for building the applications which is clearly not how it should be. Escaping both or not escaping both does not work as can be seen by the build result of the previous commits.

Edit: Found out that it is necessary because the applications are run using uses: GabrielBB/xvfb-action@v1 while domains and framework are built without that. Why do we use that @HeikoKlare?

[HeikoKlare]

We have to use the xvfb-action for both the framework and the applications because these projects contain test cases in which a non-headless Eclipse is started for which an X server is required. The domains do not require that and thus run without it.

It seems that the xvfb-run script processes the arguments in a different way than running the mvnw script plainly, so we probably need to keep these different formats for defining the paths.
At least when using the property in a local setup (i.e., on your local machine, not in GitHub Actions) this will not be an issue, as you can simply run maven also for the framework and the applications because there will be some display server already running.

[JanWittler]

Thanks for clarifying that.

[JanWittler]

Added Wiki documentation: https://github.com/vitruv-tools/Vitruv/wiki/Build-and-Continuous-Integration#github-actions