Clone, pull, and get status of a specific student on an assignment

**Is your feature request related to a problem? Please describe.**

I want to clone and pull for a specific user, not just a (effectively random) set of students per "page" of an assignment.

**Describe the solution you'd like**
A single CLI command that could print the status or, clone, or pull the submission for a specific student on an assignment.

**Describe alternatives you've considered**
Use the bulk commands and prune to what I need, or use the webapp to find the student in question.

**Additional context**
I am looking to wrap the CLI tool here into a more featureful CLI for my own specific needs and the more CLI arg nuances I can get the better :grin:. Machine readable output like JSON would be great too in this case.

The issue names the existing bulk clone, pull, and status commands, but no files or tests. Start by locating those CLI entry points and determine how a student is identified; done means one command can target that student for status, clone, or pull without relying on assignment pages, with the requested machine-readable output considered.

Written by the indexing model from the issue text.