Add a doctor command for AI assets configuration

[jakemac53]

This should validate that we can successfully load the AI assets based on the current working dir. This will help authors ensure their file is appropriately authored, and users can also ensure their dependencies don't have malformed configs.

• It could also accept a specific configuration file as a command line and just validate that one.
• It should list all the loaded configurations, and how many assets were discovered from each extension