Add sp mod

[AlexanderRichert-NOAA]

This PR puts the sp functionality under a Fortran module called sp_mod. Some downstream codes (namely UPP) will needs some tweaks as GCC at least is not accommodating of rank/type arguments in subroutine calls when modules are in play. That said, UPP builds successfully with a handful of minor changes, and grib-util, ufs-utils, and several UFS WM RTs are successfully built and tested with these changes.

Fixes #218

[Hang-Lei-NOAA]

For new application, this is good.
But when you put it into sp_mod, old/existing applications may have to add/include the sp_mod to use this version.

[AlexanderRichert-NOAA]

@Hang-Lei-NOAA it'll be similar to what developers have already had to do with the existing ip modules, in that if they want to support new and old versions, they'll need to account for it in their cmake (i.e., conditional dependency of sp depending on ip version), and add code blocks like:

#ifdef USE_SP_MOD
use sp_mod, only: ...
#endif