[backport#17260 1/3] Move wallet enums to walletutil.h

Summary:
https://github.com/bitcoin/bitcoin/pull/17260/commits/ab053ec6d1e766402f88947d29cd875a285e7280

Depends on D7118

Partial backport of Core PR17260

Test Plan:

ninja check check-functional

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D6998