Added unit test to verify how the dataset object handles comparisons

[ArlindKadra]

Reference Issue

Fixes #577

What does this PR implement/fix? Explain your changes.

Adds unit test to verify the implemented comparison for the dataset object.

How should this PR be tested?

With the newly added unit test.

[PGijsbers]

I'll wait for Appveyor to complete. Github Actions seems to fail due to too high workload on the server. I will throttle the number of parallel jobs further in the next PR :/

[ArlindKadra]

I'll wait for Appveyor to complete. Github Actions seems to fail due to too high workload on the server. I will throttle the number of parallel jobs further in the next PR :/

Yes, I also noticed that the Github Actions were failing, however, the tests that failed were not affected by the unit test added with what I saw. Let us wait for Appveyor.

[mfeurer]

I just had a look at the attributes of the dataset, and while the test obviously works, I'm wondering whether a few other attributes should also be excluded from checking, and how we would best test that?

The attributes would be _dataset, data_pickle_file, data_feather_file, feather_attribute_file. Maybe one should automatically change one attribute at a time and check that the equals comparison still works as expected?