Sort init import
# What does this PR do?

Not a high-priority item but I get bored at nights and I like writing those kinds of scripts 😅

So this PR adds a script to properly sort the import inside `_import_structure` because people have been absolutely ruthless and putting their objects in any kind of random order. That's not very feng-shui so I'm bringing back harmony by having the same sort as isort applied to all `__init__` that contain an `_import_structure`.

To address your comments on the `MakeFile`, I have removed some checks from `extra_quality_checks` because they are checks that modify content and `make quality` is only supposed to check, not change.

To have `make fixup` still work as intended, I put the checks that change content in `extra_style_checks` that is called both by `make fixup` and `make style`. Could you double-check it looks okay @LysandreJik and @stas00 ? Thanks!