Add update type 14 to jointly assimilate Tb, SM and SCF observations in single analysis

[amfox37]

Adding a new update type 14 that allows for the joint assimilation of SMAP/SMOS Tb, ASCAT SM and MODIS SCF

A relatively simple merger of existing update type 11 and update type 13 which first determines what types of observations are included in the namelist and their species number, and then loops through the tiles looking for these obs and performing snow and/or soil moisture analysis.

As commented in the code:

   ! this case is a combination of cases 11 and 13
   ! 1. obs_param%varname is checked to determine if snow and/or soil moisture obs are potentially in the analysis
   ! 2. if sm obs are in the analysis the species ID is determined for each type
   ! 3. if snow observations are in the analysis, their species ID is determined 
   ! 4. start looping through all the tiles 
   ! 5. if snow obs are in the analysis, check for snow obs with each tile, and if found perform the snow analysis
   ! 6. if sm obs are in the analysis, check for SM obs around each tile, and if found perform sm analysis
   
   ! in the case of the snow analysis: 
   ! update each tile separately using all observations associated with that tile
   ! loops through ensemble members and compute analysis separately for each ensemble member

   ! in the case of the 3d soil moisture/Tskin/ght(1) analysis: 
   ! update each tile separately using all observations within customized halo around each tile
   ! state vector differs for each tile depending on assimilated obs and soil type