🎉 Implement Visual Analysis Module

[reg1um]

This PR introduce a new visualization module to help analyze datasets more efficiently:
Added scatterplot, pairplot and kdeplot functions as well as tests and examples for their usage.

I added quite a lot of tests, which are slowing down pytest a bit, I can remove specific ones as I've seen issue #246 about tests taking lot of time.

Closes #257

[reg1um]

Also, I can revert the kokko-lib commit if it isn't necessary and is gonna be fixed soon. (it seem that it didn't even fix the github actions error...)

[codecov]

Codecov Report

❌ Patch coverage is 85.14493% with 41 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/plaid/utils/viz.py	85.03%	41 Missing ⚠️

📢 Thoughts on this report? Let us know!

[casenave]

Also, I can revert the kokko-lib commit if it isn't necessary and is gonna be fixed soon. (it seem that it didn't even fix the github actions error...)

Thanks, I've reverted the changes. Can you solve the coverage issue at #271 (comment) ? Thanks for your contribution!

[casenave]

As you mentioned, I think the testing part should be significantly accelerated. Besides, can you add the examples to the documentation as well, as for the other examples, and see if it's rendering well ? I've configure your branch to render on the docs for inspection: https://plaid-lib.readthedocs.io/en/feature-257-dataset-visual-analysis/