Prepare 0.19.0 release

[veenstrajelmer]

TODO:

• add reset function for copernicus #713
• Parse and set crs on uds upon reading mapfiles #684
• Align is_geographic with xugrid #661
• zenodo does not update anymore #647
• use pytest tmp_dir instead of manually creating and deleting output folders #734
• remove py3.8 warning from __init__.py #736
• xarray writing mfdataset results in incorrect data when not using manual encoding #239 (comment)
• solve chunking warning #679
• Improvements in copernicus-marine-client related code #694
• Correct flowelem_zcc bottom z-layer for z-sigma coordinates from reconstruction #417 >> MG? >> Improve layer reconstruction #754
• remove_edges gives unexpected behaviour for enriched rst file #680
• Fix python 3.12 testbank #551
• Generalize finding of sigma layer variables #764
• Increase minimal copernicusmarine version #692
• select more important issues
• merge PR's
• update whatsnew
• pypi via api token instead of password #732
• run entire testbank

Follow-up issue: #774