[ENH] change image logging from matplotlib figure to binary image

[broomva]

Description

This PR ...

Checklist

• Linked issues (if existing)
• Amended changelog for large changes (and added myself there as contributor)
• Added/modified tests
• Used pre-commit hooks when committing to ensure that code is compliant with hooks. Install hooks with pre-commit install.
  To run hooks independent of commit, execute pre-commit run --all-files

Make sure to have fun coding!

[fkiraly]

Thanks for the contribution and apologies for the late review.

Can you kindly explain why the title of the PR included mlflow? From looking at the code, this just seems to change how the figures are logged - as PIL image instead of as raw matplotlib figure.

Is this more compatible with mlflow? It also should be an option rather than changing and hence breaking established behaviour.