HRRR-Smoke in WRF-SFIRE

[Fergui]

Get 3D smoke from HRRR-Smoke Grib files (part of openwfm/WRF-SFIRE#47) adding a new row in Vtable:

GRIB1| Level| From |  To  | metgrid  |  metgrid | metgrid                                 |GRIB2|GRIB2|GRIB2|GRIB2|
Param| Type |Level1|Level2| Name     |  Units   | Description                             |Discp|Catgy|Param|Level|
-----+------+------+------+----------+----------+-----------------------------------------+-----------------------+
     | 109  |   *  |      | SMOKEPM  | ug m-3   | Smoke concentration                     |  0  | 20  |  0  | 105 |

Also, modify METGRID.TBL to have a new variable definition for 3D smoke from HRRR-Smoke:

========================================
name=SMOKEPM
        interp_option=four_pt+average_4pt
        fill_missing=0.
        fill_lev=200100:const(0.)
========================================