Add '-version' as command line option

[rit-clone]

Summary

Fixed #424

Changes

Added additional command line option -v & --version to retrieve currently installed version of Polypheny-DB

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ToDo

• Verify design and implementation

[rit-clone]

@hennlo Can you please review this PR and approve running workflows?

[hennlo]

@rit-clone Thanks for submitting the PR.
I've a few remarks that you could work on.

1.) Your original idea with the log.infois much cleaner to work with, therefore please refrain from using System.out
2.) You could also add a short option for querying the version, similiar to the help option you can do: -v | --version
3.) I'm afraid polyphenyDb.getClass().getPackage().getImplementationVersion() won't return Polypheny-DB's version but null.
You'll need to retrieve the version as specified in gradle.properties file. However you cannot read the file from file system and need to access the version internally.

[rit-clone]

@hennlo I'll make the changes for log.info and adding -v option as well. For point no.3, since Implementation version is referred from gradle.properties to build.gradle (https://github.com/polypheny/Polypheny-DB/blob/master/build.gradle#L25) and that version is in turn referred to dbms package's build.gradle (https://github.com/polypheny/Polypheny-DB/blob/master/dbms/build.gradle#L248) , the implementation version gets set while building. It will be null if you run it in an IDE but if the jar is run, I see the version. Will this approach not work?

[hennlo]

@rit-clone Good catch, you're absolutely right, my bad. 👍
Also I thought about the Log output and the longer I think about it I like your solution actually better.

So to summarize:
Only 2.) is open for this PR

[rit-clone]

Made the required changes. @hennlo please review.

[hennlo]

PR looks good.

[hennlo]

Thx @rit-clone, for this PR!