Add Sample Datatool

[laurens88]

Introducing a new addition for datatools, sample. Used for sampling k old, k new, and k random records from a dataset to detect concept drift.

If you could test the code for bugs and look at my section in the readme file that would be of great help!

[PeterLombaers]

Seems to work well, and this is a nice addition!

[PeterLombaers]

Two more things:

• Could you apply formatting? (see the ASReview development instructions, basically install ruff and run ruff format . from the repo root)
• A test would be nice. Just something that takes a test dataset, runs your sample tool and check that the output is in the format that you expect. You can see some examples of tests in the tests directory. If you need any help with this, just let me know!

[PeterLombaers]

Thanks for implementing this and ironing out the last details!