Returns the packed account data for a given authenticator address from the AccountRegistry contract.
Request to fetch a packed account index from the indexer.
The authenticator address to look up
"0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb"
Response containing the packed account index from the indexer.
The packed account data [32 bits recoveryCounter][32 bits pubkeyId][192 bits leafIndex]
"0x1"