Make consistent use of "pool", "address type" and "receiver type",
in RPC documentaion, and deprecate bare uses of "type" in RPC APIs.
Fixes#5534
Co-authored-by: str4d <thestr4d@gmail.com>
We also add a `type` field to the output objects (matching the field in
`z_viewtransaction`), now that the output type can't be distinguished
solely from the address encoding.