We need an endpoint that validates Modal files and extracts metadata from them if they are valid. This will be used to enhance the frontend modal app submission page.

Metadata to return will include:

• app name
• function names
• base image and pip requirements
• individual function text

This entrypoint (and the helper function that drives it) should also reject Modal apps that do things Garden doesn't want them to do. eg, setting up cron timed execution should be rejected