This reverts commit 5d13215b58f93c6be8255ef2e3e20836508c7d47.

Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>

Keep imports alphabetically sorted and their order homogeneous across
Python source files.

The isort project has more feature and is more active than the
flake8-import-order plugin.

Most issues caught were simply import ordering from the same module.
Where imports were purposefully placed out of order, tag with
isort:skip.

Trailing whitespace do not have impact on the result, they are just
unused bytes. Most text editors are configured to strip trailing
whitespaces. Remove them all in one go.

Update a handful of files to use the UNIX line ending.