Refactor / end use of "Stateful Fetch" logic

[lightwalker-eth]

Background info: Some "stateful fetch" logic was introduced for the registrar actions module. For example, see code related to StatefulFetchStatusIds.

The whole "Stateful Fetch" idea should be removed from our frontend logic and instead transition into the ENSApi backend. We should support clients making this query in a stateless way, but then return an appropriate error in ENSApi where necessary due to incompatible plugin configurations or indexing status.