Resolve "Fix bug in maven ci pipeline template"

Related issues

Closes #29 (closed)

Acceptance criteria

• Implemented code changes don't diverge from the related issue.
• Version number is incremented according to SemVer. (Snapshot versions are not merged/released.)
• Only released versions of dependencies are used (i.e. no snapshot versions).
• Pipeline still works.
• GitLab issue is up-to-date.

If necessary, the following sections have been updated:

• Readme.md

Proposed squash commit message

Add full qualified maven method name for third-party-check

Resolve reported Bug via:

• Add third-party-licenses.txt according to description in Readme.md
• Add full qualified maven method org.codehaus.mojo:license-maven-plugin:add-third-party to third-party-license-check in .gitlab-ci.yml