Helper function: toggle_extent_bounds

[tovogt]

Changes proposed in this PR:

• Building on coord_on_land: fix buffer for global grids #542, introduce a helper function that converts between "extent" and "bounds" convention for the description of a two-dimensional bounding box.

PR Author Checklist

• Read the Contribution Guide
• Correct target branch selected (if unsure, select develop)
• Source branch up-to-date with target branch
• Documentation updated
• Tests updated
• Tests passing
• No new linter issues

PR Reviewer Checklist

• Read the Contribution Guide
• CLIMADA Reviewer Checklist passed
• Tests passing
• No new linter issues

[chahank]

Why not, very useful.

Just before we close this here, is it known why CLIMADA uses both conventions? Is there a good reason for it or does legacy explains all of it?

[tovogt]

No, it's not about legacy. It's just that both conventions are used, one is usually called "extent" and the other is called "bounds". For example, in rasterio the "bounds" convention is more common (e.g. https://rasterio.readthedocs.io/en/latest/api/rasterio.transform.html#rasterio.transform.from_bounds), and in matplotlib the "extent" convention is more common (e.g. https://matplotlib.org/stable/tutorials/intermediate/imshow_extent.html?highlight=extent).

[chahank]

Yes, this is what I meant :D The fact that CLIMADA does use both conventions instead of just one is for me the legacy.