VS: Revert "Write ZERO_CHECK.proj for VS19 and above"
Revert commit 925da7d4, the main change from !6891 (merged). Although its commit message was mistakenly not updated, it implemented the change for VS 2017 and below too. Since it was merged, I've discovered several subtle failures in nightly testing with VS 2017. Revert the change pending further investigation. Keep the rest of the refactoring changes from that MR.
Edited by Brad King