Fix import * in agipdlib

Description

Going through a few CI logs, I noticed that cal_tools/cal_tools/agipdlib.py was flagged a few times due to its from agipdutils import *.
This fixes that, as well as a few other pep8 violations.

No logic changes were introduced.

How Has This Been Tested?

This was tested by running python agipdlib.py to ensure that the file can be loaded fine.

Types of changes

• Code cleanup

Checklist:

• My code follows the code style of this project.

Reviewers

@roscar @ahmedk @hammerd @schmidtp