Support different with and without hybrid benefits

[gabrielweyer]

• Support different with and without hybrid benefits instances: some instances are only available with or without hybrid benefits. I initially made the assumption that instances without hybrid benefits were a superset of instances with hybrid benefits. It turned out to be wrong.
• Discard duplicate VMs: due to what seems to be an operator error, some instance names are duplicated. As I use instance names to identify VMs and match instances, this sort of broke everything. The easiest solution is to discard duplicate instances (later on I might try to discard only the incorrect one(s)). Unfortunately it means that the duplicate instances will be missing (better not to provide any price than an incorrect price).

Example with the F16s v2 instance for the zh-tw culture without hybrid benefits:

In this example, it's obvious that the second F16s v2 can safely be renamed to L16s v2 but I need to do more analysis to determine if it's always the case.