Unit test ensuring that a tar.TypeXGlobalHeader does not cause an error

Docker-DCO-1.1-Signed-off-by: Abel Muiño <amuino@gmail.com> (github: amuino)
Ignore tar.TypeXGlobalHeader

Docker-DCO-1.1-Signed-off-by: Abel Muiño <amuino@gmail.com> (github: amuino)
Merge branch '3867-allow-pax-global-extended-headers-to-passthrough' into fixes

Docker-DCO-1.1-Signed-off-by: Abel Muiño <amuino@gmail.com> (github: amuino)