Clean-up common_factories.py

[cvicentiu]

This is one PR out of a sequence to refactor code in BB to make it more maintainable.

This commit should not cause any practical functional changes (to check windows builder paths).

A list of refactoring changes covered in this PR:

1. Eliminate star imports. Import what you use.
2. Eliminate redundant f-strings without placeholders.
3. Fix wrong escape \ character in Windows-like paths.
4. Eliminate (some) long lines over 80 characters.

NOTE: I HAVE NOT TESTED THIS COMMIT. It should be run in dev to ensure it works.

[RazvanLiviuVarzaru]

Thanks, looks good.
Before merging, let me deploy your branch in Dev, test it, and I will come up on this PR with the results.

[fauust]

Eliminate star imports. Import what you use.

👍

@cvicentiu you might want to challenge/update what's in https://github.com/MariaDB/buildbot/blob/dev/.pylintrc particularly https://github.com/MariaDB/buildbot/blob/dev/.pylintrc#L9

[cvicentiu]

@fauust thanks, there are many files still using star imports, I'll keep note to disable that once all have been cleaned.