Fre Catalog: New validator tool + new support for strict catalog generation

[Ciheim]

Is your feature request related to a problem? Please describe.
Fre-cli needs support for new methods of catalog validation

Describe the solution you'd like
A new catalog tool (fre catalog validate) that uses the comprehensive validator in the Catalog Builder repository. This will allow users to validate previously generated catalogs by hand.

Also, a --strict flag should be available to enable strict catalog generation mode.

Describe alternatives you've considered
N/A

Additional context
N/A

[Ciheim]

Addressed in #552