Explicitly add the following utilities to the ISO installer image:
    sleep, dirname, awk, cut, cmp, find, grep, mktemp, sed, sort, tr, uname, xargs, diskinfo vidcontrol

instead of symlinking to the versions of these utilities in /rescue.

This change will allow us to in future revert this change in TrueOS which added these
utilities to src/rescue/rescue/Makefile:
   https://github.com/trueos/trueos/commit/c7deb3988cbd01c34c79aaa7c4182aabbb5c92df

and minimize our differences from FreeBSD.