Merge #15947: Install bitcoin-wallet manpage

Summary:
00d110463aed12ecdc6e9c2bf47d9ef61d19fa9d Install bitcoin-wallet manpage. (Daniel Kraft)

Pull request description:

This change marks the already-existing `bitcoin-wallet.1` manpage file for installation together with the others.  Previously, only `bitcoind.1`, `bitcoin-cli.1`, `bitcoin-tx.1` and `bitcoin-qt.1` would be installed.

ACKs for commit 00d110:

laanwj:
  utACK 00d110463aed12ecdc6e9c2bf47d9ef61d19fa9d
practicalswift:
  utACK 00d110463aed12ecdc6e9c2bf47d9ef61d19fa9d

Tree-SHA512: ca846e414548f1dc774f460edca2e17d7d619c7e6f0d18db0c58c09e04f9d43c6964fcf2bacb5b1eae94de9c5fdda86abf258ef6b78b0f693715d070dfc10f08

Backport of Core PR15947

We're generating the bitcoin-wallet manpages, but they still need to be installed.

Depends on D5855

Test Plan:

sudo ninja install
man bitcoin-wallet

sudo make install
man bitcoin-wallet

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Subscribers: deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D5856