EmulatorPkg/Unix/Host: Fix NetworkPkg dependencies

EmulatorPkg/Unix/Host: Fix NetworkPkg dependencies

https://bugzilla.tianocore.org/show_bug.cgi?id=2046

* Add NetworkPkg to UNIX Host.inf dependencies
* Fix MacOS redefinition of NTOHLL and HTONLL macros
  between EDK II and standard includes in UNIX Host.h.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Andrew Fish <afish@apple.com>
Cc: Ray Ni <ray.ni@intel.com>
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>