Easy ability to run a debugger on some test

[bobbobbio]

Use Cases I am running some test which is failing but I want to debug it easily using a debugger. pytest supports this kind of thing via the --pdb CLI flag.

Acceptance Criteria We have some flag test runners accept that when provided will run the selected test in a debugger with an interactive session (just like maelstrom-run's --tty option does). For compiled languages, probably this will use gdb, for Python it should use pdb. If more than one test is selected via the filter, an error is returned instead.

Implementation Considerations We will need to somehow add layers that provide the debugger in the container. We have existing TTY features that should make the interactive part possible. This may want to go down a completely different code path in the test runner.

Definition of Done

• [ ] CHANGELOG.md updated.
• [ ] Documentation in doc/book/head updated.
• [ ] Issue is in the correct milestone.