[wallet] Don't read acentry key-values from wallet on load.
Summary:
Partial backport of Core PR13825
https://github.com/bitcoin/bitcoin/pull/13825/commits/a544ab28572de96f3ea0855592abd655ef5d937
Depends on D5316
Test Plan:
ninja check test_runner.py wallet_*
Reviewers: O1 Bitcoin ABC, #bitcoin_abc, Fabien
Reviewed By: O1 Bitcoin ABC, #bitcoin_abc, Fabien
Subscribers: Fabien
Differential Revision: https://reviews.bitcoinabc.org/D5415