Backports the following to the 0.19 branch:
- #17946 - Fix GBT: Restore “!segwit” and “csv” to “rules” key
- #18160 - gui: Avoid Wallet::GetBalance in WalletModel::pollBalanceChanged
- #18425 - releases: Update with new Windows code signing certificate
- #18676 - build: Check libevent minimum version in configure script
- #19097 - qt: Add missing QPainterPath include (as per #19510)
- #18640 - appveyor: Remove clcache
- #19444 - test: Remove cached directories and associated script blocks from appveyor config
- #19612 - lint: fix shellcheck URL in CI install
- #18001 - Updated appveyor job to checkout a specific vcpkg commit ID
Closes: #19510.