List all projects belonging to an account

[brokad]

Currently there is no way to list all projects that belong to a single account. We'd like a subcommand of cargo shuttle project like cargo shuttle project list that prints out all the projects that belong to the calling account.

This will require extending the /projects API endpoint with a GET that returns an array of project::Response for all the projects that belong to this account. Then, a client-side change will be required to add the list subcommand that consumes that new endpoint via the client and prints out the result in a nicely formatted way (maybe the same tabular format we use for deployment list?).

[emmakuen]

@brokad, I'll work on this issue.