cmake: update FUSE_INCLUDE_DIRS to match autoconf

cmake: update FUSE_INCLUDE_DIRS to match autoconf

client/fuse_ll.cc is now including <fuse.h> and <fuse_lowlevel.h>
instead of <fuse/fuse.h> and <fuse/fuse_lowlevel.h>, so we need to add
the fuse directory to the FUSE_INCLUDE_DIRS variable

using find_path() with just fuse.h was finding a /usr/include/fuse.h
instead of the one in /usr/include/fuse/. looking for fuse_common.h and
fuse_lowlevel.h first causes it to generate the correct
FUSE_INCLUDE_DIRS=/usr/include/fuse

Fixes: #12909
Signed-off-by: Casey Bodley <cbodley@redhat.com>