Add a command-line flag to sort __all__ re-exports (#1862)

[parafoxia]

This PR adds a --sort-reexports CLI flag and the respective cfg and toml options to isort, which allows for similar behaviour to # isort: [list|tuple|dict] without the need to have comments scattered around. See #1862 for more information.

This PR makes no attempt to document this feature at present, but I'm happy to do this if you'd like me to.

Closes #1862.

[parafoxia]

Also, for some reason, the test_importable test fails when localling running pytest. I'm not really sure why this is, but I haven't attempted a fix as I believe it's outside the scope of this PR, and the failure is likely not caused by it.

[codecov]

Codecov Report

Merging #1863 (3cac920) into main (4e23fcf) will decrease coverage by 0.29%.
The diff coverage is 50.00%.

@@            Coverage Diff             @@
##             main    #1863      +/-   ##
==========================================
- Coverage   99.83%   99.54%   -0.30%     
==========================================
  Files          38       38              
  Lines        3054     3070      +16     
  Branches      728      730       +2     
==========================================
+ Hits         3049     3056       +7     
- Misses          1        8       +7     
- Partials        4        6       +2     

[timothycrosley]

Thanks for this improvement! The tests pass in CI and locally for me, so I'm sure its just because of the state of local venv, maybe not using poetry or not using ./scripts/done.sh?

[parafoxia]

I was using Poetry, but didn't realise that other script was there, so probably was something to do with that. I did initially try to install everything without Poetry cos I can't for the life of me get it to work on 3.10, but pip wouldn't install everything, so not sure what's going on there.

And no worries! Lib has been super useful to me for a while so thought I'd give a little back ^-^