Use enum choices rather than DB values
Use enum choices rather than DB values

By using DB values, a 400 response was returned when attempting to
filter by a value not in the DB even if it was defined on ActionType.
This fixes this so that a 200 response would be returned with empty
results as long as the action type is valid.

DemocracyClub/yournextrepresentative,DemocracyClub/yournextrepresentative,DemocracyClub/yournextrepresentative