Add reinstall command

[cs01]

How would this feature be useful?

per @sahensley 's comment in #246

Also, a bit of a side trek but would it be worth introducing reinstall for an individual package? I could possible see a need if only certain venvs were made with a Python interpreter that is no longer present but it may be a bit of a niche case. The instance I've run into this when I've had multiple Python versions compiled via Pyenv.

Describe the solution you'd like

Add top-level reinstall command, as an alternative to the reinstall-all command.

Describe alternatives you've considered

Uninstall then reinstall the package, but that is not super very friendly.

[itsayellow]

This makes sense to me. Especially combined with pipx reinstall-all --skip.