Add unit tests for dough-data

[md5sha256]

Waiting on #62 to be merged as this includes the tests for CopyUtils.

Whilst the PR has enough tests, there is room for improvement in the quality and (potentially) necessary documentation of the tests.

This PR adds tests for the blocks and collections packages in dough data alongside data.TriStateOptional. ~~That being said, there aren't any tests for the persistence package. ~~

I'm hoping once https://github.com/MockBukkit/MockBukkit/pull/244 is merged I can start working on writing tests for PersistentDataAPI.

I haven't added @Displayname annotations to the tests consistently but there are a few which do have them.

This brings us up to 88% class coverage and 75% lines covered.

[sonarqubecloud[bot]]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

100.0% Coverage
0.0% Duplication

[J3fftw1]

Marking this as stale The repo is no merged to the Slimefun org so it should be reviewed faster in the future.