Remove public inputs calculation from nightfall-client transfer service

[Westlad]

The calculation of public inputs in the transfer.mjs service is incorrect; it includes the ercAddress variable, which must be hidden for a transfer transaction. The ZKP layer is correct however and does not expose ercAddress.

This works because the public inputs are only really used to derive the L2 transaction hash and, although this value is incorrect for a transfer, it's not used offchain anywhere.

We should remove this incorrect code, even though it currently appears to have no deleterious effect, it may be assume correct in future.