Allow selective piggyback data to be sync across customers in Ultimate with MT

Currently the implemented piggyback hub for syncing piggyback data across sites is limited for logical reasons on Ultimate with MT to only allow syncing data between sites of the same customer.

This can pose a problem for MSP's as we sometimes have shared resources that can provide piggyback data to multiple customers from the provider customer.

Two examples just from my point of view would be vCenter and Veeam. Both these checks provide piggyback data for VMs. Both these services would live in the Provider customer or a sub-customer for hosting services and as such the piggyback data that these servers could provide for customer VMs inside the different customers would not be usable currently due to the inability to sync piggyback data between customers.

That would mean we would either resort to the legacy method of syncing piggyback files manually with some filter or not have it at all.

It would be benificial to provide a filterable, limited way of selecting some data to sync to a different customers site still utilizing the piggyback hub but also respecting the data tenancy system provided by Ultimate with MT.