Improve download files page layout

[nlhkabu]

Closes #18732 and #18796

[nlhkabu]

WIP:

TODO:

• Update select to show values in "pretty" format - e.g. CP26 becomes CPython 2.6
• Update table to show values in "pretty" format - e.g. CP26 becomes CPython 2.6
• Show "No files match your selection" message when user filters by a combination which returns no results
• Limit the filters based on what the user has already selected
• Provide quick option to reset the filters (?)
• Update URL based on filters

[nlhkabu]

Question how should we format the ABI?

Example options for the ABI cp36m:

OR

OR

OR

[merwok]

IMO it should not be just m (pymalloc), but needs to include all the parts: m and other modifiers don’t make sense without the first part cp36.

Unless it’s guaranteed that an abi tag cp36m always has an interpreter tag of cp36, but I am not sure about that.

[nlhkabu]

Ok, thanks for your feedback @merwok, and for your comments on the associated issue.
I've added "Update URL based on filters" to the TODO list

re: ABIs, I've added a couple more options above - based on your feedback, I think the third option is best: CPython 3.6m (pymalloc)

[di]

@nlhkabu We might want to address #18796 here as well.

[miketheman]

@nlhkabu We might want to address #18796 here as well.

Looks like there's a clause for this being added - https://github.com/pypi/warehouse/pull/18741/files#diff-057bf4a747c150d9f3f76db209a6c8f689b023a8e7cd41d96fcc549492889da7R563 - maybe instead of 3, 1 is a better value?

[merwok]

I suggested 3 as threshold: it’s not useful to filter a list of 1 item, or 2 items.
(One could argue for a minimum of 5 or 6 as well!)

[nlhkabu]

Yep, currently only showing the filters when there are more than 3 wheels, but happy to adjust that value based on feedback :)