During install dracut will generate a generic (i.e. large) initrd.
As we now start udev early, we can use udev metadata when generating
our initrd and thus we can generate our default, hostonly initrd.

Thus ensure relevant directories (/run) are bind mounted and fake a
/run/initramfs folder which is used in dracut to detect a boot
which will have sufficient metadata in the udev DB.

Tested with an install on a new disk and creating LVMs and
also on an install where the pre-existing LVMs were reused.

Suitable fixes to drakx-in-chroot have also been added, but
remain untested