unfs3, unfs-server: Replace all instances of unfs-server with unfs3

unfs3, unfs-server: Replace all instances of unfs-server with unfs3

Other recipes dependencies and even some comments need to be updated
for the removal of unfs-server and the replacement with unfs3.  The
unfs3 is a complete drop in replacement providing all the prior
functionality of NFSv2 but also adding NFSv3.

[YOCTO #5639]

(From OE-Core rev: d577c56519a448b142da5b43e46d5bd9d3a3b4bd)

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>