Used by the ENS manager to set an external service to be used as ENS mapper.
)publicviewreturns(address result,uint8 ensType)
Validates and returns the address of a given ens hash.
ENS type is also returned: external, local or library.
Library is a local ENS that points to a special contract that runs in the context of the FCT_Runner (delegate call)
Library ENS starts with "@lib:"
When "expectedAddress" is 0x0, validation is bypassed
If ENS is not fund on the local mapping, calls the external ENS contract.