[Feature Request]: Remove mongogrant dep

[jmmshn]

Problem

I think the percentage of people who actually get their credentials from Mongogrant is going to decreasing and most people are just using mongogrant as a shorthand for their credentials (or to anonimize it for demonstration and sharing code)

Proposed Solution

It might make sense to remove the dependency and just move the parsing of the code over to maggma.

Alternatives

save this for a hackathon?? Plan chackathons?