Switch to palantir-java-format

[koppor]

This is IMHO a follow-up to https://github.com/koppor/jabref/pull/663.

TODO: Compare with eee93f3 (#663)

Blocked by https://github.com/palantir/palantir-java-format/issues/977.

Mandatory checks

• [ ] Change in CHANGELOG.md described in a way that is understandable for the average user (if applicable)
• [ ] Tests created for changes (if applicable)
• [ ] Manually tested changed features in running JabRef (always required)
• [ ] Screenshots added in PR description (for UI changes)
• [ ] Checked developer's documentation: Is the information available and up to date? If not, I outlined it in this pull request.
• [ ] Checked documentation: Is the information available and up to date? If not, I created an issue at https://github.com/JabRef/user-documentation/issues or, even better, I submitted a pull request to the documentation repository.