HTML escape the wallet name in dialogs and notifications

Summary:
Qt interprets HTML and uses the first ampersand in a string to specify hot key.
Escape HTML and ampersands in wallet names to display them unambigously.

Backport of Core PR16826

Test Plan:
ninja && ninja check

Run bitcoin-qt and create a new wallet called "Hel&lo <b>World</b>,
and make sure it is display as a raw string everywhere
(send transaction dialog, Open Wallet menu)

Reviewers: O1 Bitcoin ABC, #bitcoin_abc, deadalnix

Reviewed By: O1 Bitcoin ABC, #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D7931