Add --repo filter to more gh codespaces commands

[cmbrose]

Fixes: #6548

This adds a new -r/--repo argument to many codespace commands which don't already have it - code, stop, jupyter, ssh, etc. The argument pre-filters the codespace selection list and, if there is only a single codespace for the repo, automatically selects it.

See the example below which showcases:

• Selecting a repo with multiple codespaces results in a prompt for only those codespaces
• Selecting a repo with no codespaces results in a you have no codespaces error
• Selecting a repo with a single codespace immediately opens it with no prompt

Note selecting both --codespace and --repo for these commands doesn't really make sense and so doing so results in an error:

[cmbrose]

Note that I do intend to add tests for this, but wanted to get sign off on the approach first 😄

[cmbrose]

cc @cli/code-reviewers - would appreciate feedback here when possible

[samcoe]

@cmbrose Sorry for the delay in taking a look at this. I think what you have and the path you are taking works but in my comments I propose a different approach to the problem which I think would be easier to use as well as maintain in the future. Let me know if you have any questions about my comments.

[cmbrose]

@samcoe thanks for all the help on this review! It should be in a good state now for a last review 😄

[samcoe]

@cmbrose This looks awesome, 🚢. Thanks for being patient with the review cycles.

[jungaretti]

This looks great! You used elegant patterns that we can use in other places too.