Re-organize the CLI commands by topic

[nalourie-ai2]

The amti CLI has grown a number of commands (14 by my current count). Grouping the commands hierarchically into several topics would present a friendly help interface to users.

I'd tentatively suggest grouping the commands into qualification, batch, and worker groups. If valuable, the new organization can be discussed further on this issue. Also, after grouping the commands, it might be helpful to rename some of them to eliminate redundancy. For example:

• amti create-batch to amti batch create
• amti status-batch to amti batch status
• amti delete-batch to amti batch delete
• etc.