Add option Temporary Directory

[ThomasBouche]

What?

When calling the get_coverage and get_combined_coverage methods, add an option temp_dir to add a temporary path if the user does not have write permission to the default temporary dir.

Have you done?

• Code tests
• Update documentation
• Update changelog

Tests on tutorials

Details to be checked:

I've created several conditions in the function in the _grib_bytes_to_df method for deleting temporary files and folders.
I thought that if the user entered the project dir and not a temporary dir, the project could be deleted.
That's why there's a subdir and then a deletion mechanism depending on whether the temp_dir already exists or not, to delete everything that isn't necessary.
i'd be happy to receive feedback on the choices made.

Linked issues:

• Close Suggestion to Customize Temporary Directory #28

[GratienDSX]

Mostly docstring changes, and one question.