Adopt cookiecutter-uv as foundational environment

[reece]

Replacement for #55.

Instead of updating the existing python package template, adopt cookiecutter-uv as the foundation. Migrating all of the packages to a cookiecutter-backed template straight away would be a big lift. Instead, let's use an intermediate repo (based on biocommons.example), and then use that to sync with project repos.

Specifically:

• Fork fpgmaas/cookiecutter-uv into biocommons/python-package-cookiecutter
• Rename biocommons.example to biocommons/python-package. Use this as the test package for evaluating the resulting environment.
• Create a branch in b/p-p (attached to this this issue) and populate/replace the branch with most of the files from the instantiation of the cc template.
• Selectively merge files from the branch into main while monitoring the ability to build the resulting pypi packages
• Incorporate other changes (e.g., from @jsstevenson) into p-p

This issue will be done when the p-p repo is operating as expected and ready for adoption by other repos. (Exact criteria TBD.)

Related but separate work:

• Backport changes in p-p back to the p-p-cookiecutter repo
• Manually merge from the python-package repo into each repo. When complete, do a minor version bump release.

[reece]

This was completed a while ago. The template is currently this repo itself rather than a cookie cutter template (for now).