Add "install-all" command to install packages according to spec metadata file

[huxuan]

• I have added a news fragment under changelog.d/ (if the patch affects the end users)

Summary of changes

Fix #687

Test plan

Tested by running

pipx list --json > pipx.json
pipx install-all pipx.json

Known issues

1. pipx install --force without --python complains about the ignorance of --python #1304
2. Can not move utility functions to pipx.util due to circular import problem. Add "install-all" command to install packages according to spec metadata file #1301 (comment)

[chrysle]

Thank you for this piece of work, it will come in handy! Could we have an example in docs/examples.md?

[chrysle]

Could you move the two helper functions to util.py? We're trying to keep the command files as clear as possible.

[huxuan]

Could you move the two helper functions to util.py? We're trying to keep the command files as clear as possible.

After moving the two utils to pipx.util. from pipx.pipx_metadata_file import PackageInfo, PipxMetadata, _json_decoder_object_hook will import PipxError before it is initialized which will lead to "circular import" problem. Any ideas?

Maybe we need a pipx.model for those entities? If so, I would suggest to do it in a separate pull request.

[huxuan]

I find some bug for the python args, will request another review when fix that problem.

[huxuan]

@chrysle All comments except for moving the utility functions should be done. PTAL :-)

[chrysle]

Maybe we need a pipx.model for those entities? If so, I would suggest to do it in a separate pull request.

Sounds good, let's keep it like this for now.