This reverts commit a7c5d887e943aa51f2270e517954c024a8c01500.

`flake8` seems to dislike the formatting of black.

That way people who use it won't be deterred, while it unifies style
everywhere.

This reverts commit 53d94b8091b36847bb9e495c76bb5a3ec2a2fdb5.

The reason for the revert is that the commit in question introduced a
regression where certain modules, functions and classes that were
exposed before were no longer exposed.

See https://github.com/gitpython-developers/GitPython/pull/1352#issuecomment-932757204
for additional information.

All `from <module> import *` has now been replaced by
`from <module> import X, Y, ...`.

Contributes to #1349