Address updated matplotlib syntax

Matplotlib has made some small syntax changes to its error messages that causes the pipeline to fail (more than initially found in !317 (merged)). These are specifically:

• set_title now returns 'got an unexpected keyword argument' instead of 'has no property' → tests adjusted accordingly
• Seaborn styles have been shelved → base_style default setting in base_plots.yml is removed
• Deprecation of matplotlib.cm.get_cmap → Use matplotlib.colormaps registry instead
  • Removes lut as possible argument (very minor breaking change: should not have been exposed in the first place, so it's ok to keep this as a patch version bump)

Can this be accepted?

• Changes implemented
• Pipeline passing
• Reviewed and approved
• Version bumped
• Changelog entry added
• History cleaned up