Merge #14282: [wallet] Remove -usehd

Summary:
7ac911afe7 [docs] Add release notes for removing -usehd (John Newbery)
25548b2958 [wallet] Remove -usehd (John Newbery)

Pull request description:

`-usehd` is no longer used (except to tell the user that they've set it incorrectly for the wallet that they're loading). Remove it (in the same spirit as #14272)

Tree-SHA512: 5bdcd2bb9bb8504a01343595bcd1bd433d97b730255152c725103c1ac3fa3a9d9e5220a4c29d4c72307cf803e1c09d31080f83603c23dc77263846e17b1826f0

Backport of Core PR14282

Test Plan:

ninja check
ninja check-functional

Reviewers: O1 Bitcoin ABC, #bitcoin_abc, deadalnix

Reviewed By: O1 Bitcoin ABC, #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D5488