In addition to changing the build-type dependent build directories, we
can take this opportunity to move the vcpkg cache directory to the Build
folder itself. This probably isn't 100% needed, but it ensures that no
leftover artifacts are used from non-dynamic vcpkg builds, and it's also
generally nice to have all build artifacts under Build.
This ensures that vcpkg downloads and builds all dependencies for
Android. We add it as a CMAKE_TOOLCHAIN_FILE that then chainloads the
Android NDK's toolchain file, as per the vcpkg documentation.
