Add static code analysis as part of the build

Add static code analysis as part of the build

Motivation:

There was no continuous static code analysis until now. This is an important part of the quality assurance and should be covered in all builds

Modifications:

• add configuration for static code analysis as part of the Maven build
• add the neccessary GitLab configuration

Result

Static code analysis can be executed from the command line and the execution as part of the CI is prepared and only needs to be aenabled

Target: master

Request:

Acked-by:

Pull-request: !3 (merged)