feature: store version update source in embed JSON file

[mayeut]

Store version update source in embed JSON file.
For now, the source can take the value periodic or manual (not enforced to allow future sources).
Only periodic & manual sources are allowed to provide an update path for a bundle version.
Running a manual update marks all versions source as manual.
Running a periodic update marks all versions source as periodic if the source value is not manual.

The following issues are fixed:

• fixes virtualenv always switch back to embedded wheels after a recent periodic update  #2265
• fixes new patch versions of pip, setuptools & wheel are not considered for 28 days #2266
• fixes manual upgrades are discarded once a periodic upgrade is done #2267

This will also allow to implement #2268 with a new source (e.g. download).

Thanks for contributing, make sure you address all the checklists (for details on how see

development documentation)!

• ran the linter to address style issues (tox -e fix_lint)
• wrote descriptive pull request text
• ensured there are test(s) validating the fix
• added news fragment in docs/changelog folder
• updated/extended the documentation

[gaborbernat]

@mayeut hey thanks for the great contributions, I'd be happy to have you along as co-maintainer for the project if you're interested 👌

[mayeut]

I'd be happy to have you along as co-maintainer for the project if you're interested

@gaborbernat, thanks for the offer but I've got my hands full with other open source projects (& the day job) so I'll probably not be useful as a co-maintainer. I will continue contributing once in a while depending on those other projects needs (mostly cibuildwheel w.r.t. virtualenv). I see this PR as a way towards #2268 so it was not really to fix issues that I opened it but rather to enable the enhancement.

[gaborbernat]

Sounds good 👍 and if you change your mind the offer stands. No pressure.