Restore warning for cookbook shadowing
Tidy cookbook upload specs
Add regression test for cookbook overlay warning
Add changelog note about cookbook overlay warning
Merge branch 'restore-shadowing-warning'

Commit cf8af09a40e5fd9fff8d1c481fb98b017545f49b removed warnings related to the
cookbook overlay/shadowing feature, so they have been missing since Chef 11.0.
Add them back.
CHEF-5087: Add a Windows Installer package provider

Adds the framework for a windows package provider, which must determine the
correct provider by examining metadata about the source file, or the source
file itself.

Provides FFI based access to the Windows Installer functions to retrieve
metadata from the MSI files and from the Windows product database.

Combines both of these into an MSI package provider.

Continues to work alongside the windows_package LWRP.
CHEF-5087: Hide win32 if not on windows