[backport#15450 5/5] Add Create Wallet menu action

Summary:
Co-authored-by: João Barbosa <joao.paulo.barbosa@gmail.com>

https://github.com/bitcoin/bitcoin/pull/15450/commits/613de61a04c210a51af9997e69f66439a17a632a

Depends on D7105

Concludes backport of Core PR15450

Test Plan:

ninja check check-functional

Used the bitcoin-qt wallet on regtest mode to create wallets and make sure behavior is expected

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D7106