Enhancement: add support for /api/v1/volume-purchasing-locations

[ecanault]

Hi,

The endpoint /api/v1/volume-purchasing-locations exists in the SDK but not yet in the provider.

Even if the creation of VPP tokens can not be done automatically as it requires ABM / ASM access, gathering informations about them will permit for example to know the expiration date of the token or update an existing token after downloading it from Apple servers.

Thanks,
Emmanuel