Ability to set an "endorsed SP"

[BigLep]

TODO: @rvagg to describe the user experience he thinks we'll want

[rvagg]

• Three tiers of SPs: all SPs -> approved (decent service) -> endorsed (golden, trusted, also "approved")
• An endorsed gets first copy of every piece by the default SDK upload path, an approved gets second copy
• Devnet should have the ability to specify how many SPs go in to the endorsed contract
• Owner does a addProviderId(id):
  • https://github.com/FilOzone/filecoin-services/blob/main/service_contracts/src/ProviderIdSet.sol
  • https://github.com/FilOzone/filecoin-services/blob/main/service_contracts/abi/ProviderIdSet.abi.json

Synapse will expect this to exist (although it may have a fallback for no-endorsed-found).