pkg mods: latest_version: (1) always allow refresh arg (2) error on invalid kwargs

A majority of package manager modules support a `refresh` argument to `latest_version()`. For the sake of API uniformity, this commit adds explicit support for allowing `refresh` as a no-op argument to the remaining modules.

With that in place, this commit also adds (wherever easily possible) extra error checking for unsupported keyword arguments (so that typos will be reported instead of silently ignored).

#warOnKwargs