[Feature] Functionality to validate an newly-generated local atlas given a path

[alessandrofelder]

Is your feature request related to a problem? Please describe.
Our validation functions take a BrainGlobeAtlas object. It is unclear to me how easy it is to run them on an atlas that exists only locally - ie when we package a new (version of an) atlas, but before we upload it to GIN.

Describe the solution you'd like
This issue will be addressed when it is possible for an atlas packager to run any or all validation functions on a newly generated atlas. This should be as easy and well-documented as practical. Maybe this can be part of the template script even.

Describe alternatives you've considered
Maybe it is sufficient to copy the folder of the newly-generated atlas into the BrainGlobe directory?
This should be documented if so.