If validator is not in the validator set, validator stats are not retrieved

Ensure that the validator stats can be retrieved even if the validator is not in the validator set. Also add a new data point to indicate that if the validator is in the set or not.

Start by locating the validator-set filtering and validator-stats retrieval paths, then inspect how existing validator data points are represented. Done means stats are available for validators outside the set and a data point indicates set membership; run the repository's existing tests to verify both cases.

Written by the indexing model from the issue text.