Clean up code around create_sorting_analyzer and create/load_* functions in sortinganalyzer.py

[ecobost]

This PR does not functionally change much. It is mainly for code refactoring and to improve legibility.

The only two functional changes are:

• fix small bug when calling save_to_zarr("test.zarr") would add an extra .zarr to the filename (

  spikeinterface/src/spikeinterface/core/base.py

  Line 1087 in 39dfac4

  zarr_path = cache_folder / f"{name}.zarr"

  )
• when return_scaled and return_in_uV are provided, prioritize return_in_uV. Currently, it prefers return_scaled over return_in_uV

Code quality improvements:

• type hinting
• Collect code into logical blocks (e..g, everything that has to do wit main indices together); add comment headers (e.g., Saving main indices) and reorder this blocks (e.g., expected stuff like sorting should be saved and loaded before any of the optional things like sparsity)
• Make create_binary_folder parallel create_zarr (you can now see how they are both doing exactly the same).
• Make load_binary_folder parallel load_zarr.
• Preserve the same order of operations when loading and saving. If sorting was saved first, then load first and so on.
• Tighten code when possible

[zm711]

A few initial comments.

[zm711]

where did this else go? If a name is specified we should accept their name right? I haven't read this for a while.

[ecobost]

logic before was if name is None, -> [create random name as name, create zarr_path] else [create_zarr_path]. Now, the logic is if name is none-> [create_random_name] -> (always) create_zarr_path. The only difference is in whether something is printed. Assuming verbose=True, before if name is None, print "using zarr folder", else if name was provided but not is_set_global_tmp_folder, then print "using zarr folder..." , now it always prints (when verbose=True). I think it's worth it for simpler code

[zm711]

There was some debate about whether people liked this or not. Someone else had proposed doing this and we decided against it at the time, but maybe people have changed their minds?

[ecobost]

Otherwise I had to repeat Literal["both", "neg", "pos"] in a bunch of places. And in theory if later an option was added to the list also add that option in a bunch of places. I'm ok either way, it's just variables

[zm711]

why this change? is_dir() verifies existence and that it is a folder? So it's more specific.

[ecobost]

In here particularly, we don't actually care about it being a directory because we are gonna delete it anyway (whether a fle or directory); but actually we use exists everywhere so I'll change the ones where isdir/isfile will be more appropiate

[zm711]

Why remove the politeness?

[ecobost]

I thought Consider re-generating was weak enough already :) and more direct. We are not even telling them to re-generate it but to consider it, Won't die on this hill though