Reformatted Java code and added .editorconfig

[Bert-R]

The formatting of the Java code is consistent now, and described in an- .editorconfig file. Next to that, all wildcard imports are replaced with specific ones.

This is a first step toward increasing the consistency of contributions. These are the next steps that I propose to take:

1. Extend the pull-request-check with the Super-Linter, with the editorconfig-checker enabled.
2. Create a CONTRIBUTE.md that describes guidelines and instructions for contributions
3. Create a SonarCloud project and add rules to automate code reviews
4. Increase test coverage
5. Make it a rule that PRs come with automated tests

[davideicardi]

@Bert-R Nice! Agree with your proposals.
Just a question: what Sonar Cloud will offers that cannot be done with a traditional local linter/code analyzer?

[Bert-R]

SonarCloud gives insight in the state of the product and the evolution over time, it provides the feedback on a PR in a nicer way and it gives an easier way to maintain the rules.