[attestation]: levies and authorities

[koolamusic]

Attestations that require a levy should only be created by authorities. however given the fact that a schema can be created by anybody, this will not be enforced, thus we have two options

Option 1:

A schema that requires a levy should use a custom resolver implementation to handle all of the logic around collection of their levies.

Option 2:

Only allow verified authorities use our payable_resolvers to collect levies for their attestations.
This helps in creating a value add for "verified authorities" and also incentivise our development efforts for the security and robustness of default_resolvers