reinstall-all lost injected packages.

[MisLink]

In my case, I always inject a lot of flake8 plugins to flake8.

Would it be possible that injected packages should be recorded so that it is clear which ones should be reinstalled together?
Furthermore, it would be a big help if there's an extra option that pipx does the job.

[cs01]

I think this can be done by capturing the output of pip freeze before uninstalling, then running pip install on its output when reinstalling. I will add this.

[itsayellow]

fixed via #222