Support for optional python_site_packages_path in repodata

[Hind-M]

Hello there,
There is a CEP that we are trying to implement in mamba to add support for the optional python_site_packages_path field in repodata.

We are already using SOLVABLE_MEDIADIR for the platform/ subdir and SOLVABLE_MEDIABASE for the channel.
Any suggestions on a relevant constant to use? Or should we add a specific field to support it in libsolv?

Thanks!