[backport#16394] Allow createwallet to take empty passwords to make unencrypted wallets
Summary:
Allow createwallet to take empty passwords to make unencrypted wallets (Andrew Chow)
Pull request description:
Allow createwallet to take the empty string as a password and interpret that as leaving the wallet unencrypted. Also warn when that happens. This fixes a bug where it was not possible to use the `avoid_reuse` option for new unencrypted wallets without using named arguments.Thus this allows more `createwallet` options to be added that can be set on unencrypted wallets when using positional arguments.
https://github.com/bitcoin/bitcoin/pull/16394/commits/c5d37873677551caac34752214dd491f5278c8d5
Backport of Core PR16394
Test Plan:
ninja check ./test_runner.py wallet_createwallet
Reviewers: #bitcoin_abc, jasonbcox
Reviewed By: #bitcoin_abc, jasonbcox
Differential Revision: https://reviews.bitcoinabc.org/D7108