[backport#16399 3/3] Use switch on status in RpcWallet

Summary:
https://github.com/bitcoin/bitcoin/pull/16399/commits/e967cae8fac84ec7a89a3a853a83d8193ac3308e#

Depends on D7036

Concludes backport of Core PR16399

Test Plan:

ninja check check-functional

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D7037