msvc warning C4834 for the Bitcoin Core build was introduced by Visual Studio 16.4.0. This PR adds an ignore rule for the warning (it's related to the nodiscard attribute and is not considered relevant).
An additional side effect of the msvc compiler update is the prebuilt Qt5.9.8 libraries cannot be linked due to being built with an earlier version of the compiler. To fix this a new Qt5.9.8 version has been compiled and the appveyor job updated to use them. The GitHub Actions job needs to continue to use the original Qt5.9.8 libraries until the latest GitHub Windows image also updates to >= Visual Studio 2019 v16.4.
- Update build image from Visual Studio 2017 to Visual Studio 2019.
- Updated Qt static library from Qt5.9.7 to Qt5.9.8.
- Added commands to update vcpkg port files (this does not update already installed packages).
- Updated vcpkg package list as per #17309.
- Removed commands setting common project file options. Now done via common.init.vcxproj include.
- Changed msbuild verbosity from normal to quiet. Normal rights a LOT of logs and impacts appveyor job duration.
Updated msvc project configs:
- Updated platform toolset from v141 to v142.
- Updated Qt static library from Qt5.9.7 to Qt5.9.8.
- Added ignore for linker warning building bitcoin-qt program.
- Added missing util/str.cpp class file to test_bitcoin project file.
Aaron Clauson