Tweak LVM partition scheme needles a bit
    
    In https://openqa.fedoraproject.org/tests/1938847 , we wound up
    doing an LVM thinp install when we meant to do a regular LVM
    install, because LVM was already highlighted (for some reason)
    in the scheme list, and the "LVM" needle is narrow enough that
    it matched on the start of "LVM Thin Provisioning".
    
    To avoid this, we make the match area in the existing needle
    wider so it can't match on "LVM Thin Provisioning", and add an
    alternate needle for LVM when it's highlighted.
    
    Signed-off-by: Adam Williamson <awilliam@redhat.com>