rename fre/pp/*.py files to not clash with click cli command names.

[ilaflott]

Describe your changes

see title

Issue ticket number and link (if applicable)

see PR #278

Checklist before requesting a review

• I ran my code
• I tried to make my code readable
• I tried to comment my code
• I wrote a new test, if applicable
• I wrote new instructions/documentation, if applicable
• I ran pytest and inspected it's output
• I ran pylint and attempted to implement some of it's feedback

[ilaflott]

should be good!

the wrapper makes it to submitting jobs, unfortunately, the pp-starter jobs are failing.