[rpc] fundrawtransaction, walletcreatefundedpsbt lock manually selected coins

Summary:
Previously only automatically selected coins were locked when lockUnspents is set.
It now also locks selected coins.

This is a backport of core#18244

Test Plan: ninja all check-all

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D10144