Add registrar index.

Indeed, as PyFunceble officially provides a way to provide the registrar,
we should also expose the index here.

Author: funilrys

pyfunceble_webworker/models/availability.py

@@ -178,6 +178,7 @@ class AvailabilityStatusExtended(AvailabilityStatusBase):
     url_syntax: Optional[bool] = None
 
     expiration_date: Optional[str] = None
+    registrar: Optional[str] = None
 
     status_before_extra_rules: Optional[str] = None
     status_after_extra_rules: Optional[str] = None

pyfunceble_webworker/models/records.py

@@ -74,3 +74,4 @@ class StatusWhoisLookupRecord(BaseModel):
     subject: Optional[str] = None
     record: Optional[str] = None
     expiration_date: Optional[str] = None
+    registrar: Optional[str] = None