Expected behaviour of priv_getTxCount
If the request has from/to fields, it should return the number of private transactions in the legacy privacy group for that participants (merge priv_getTxCount with eea_getTxCount)
If the request contains a privacyGroupId, it should return the number of transactions for that specific privacy group.
update Besu priv_getTxCount with the desired behaviour and delete eea_getTxCount
Update EthSigner to use priv_getTxCount