ENG-8371 Refactor Group Type for groups list function

Tilting at windmills?

- Andrii Pleskach advised Alden Jenkins to work with me to refactor a really

messy function in the `group/utils.py` file. Curiously I wasn't the primary

author (or the author at all) of the function. Yet it was still a fun project.

- Turns out I love a good refactoring.

- There's a flag `show_all_group_types` that is set to true if there's a group

type name sent in to filter on. But it could also be True simply by having

that value sent into the function. So you can force showing all group types,

or have it triggered by your filter.

- I'm not crazy about the design of this logic. But really, it just makes me

want to be better about breaking my own logic up.