[SHELL32] Better determine whether to hide or show shell-folder namespace items (#9046) In `SHELL32_IsShellFolderNamespaceItemHidden()`, use `SHRegGetBoolUSValue()` to look at both `HKEY_CURRENT_USER` with fallback to `HKEY_LOCAL_MACHINE`, when searching for the registry value that determines whether a shell-folder namespace item is to be hidden or shown. Behaviour confirmed on Windows 2003. Addendum to commit 6ae11ba09d (PR #7189). […]