hasura migrate reset

This command should clear the history of the migrations on the server and clear the local migrations. Basically, do steps 1 and 2 mentioned in this blog post: https://hasura.io/blog/resetting-hasura-migrations/

What would you like to be added:

Currently config uses one file per environment (eg. dev, staging, prod, etc) we should move to a multi-file config where we have one folder per environment and config values can be split across multiple files within this folder.

Why is this needed:

For setups where there are