[FEATURE REQUEST] Remove the Emissions Menu in input.geos

[msulprizio]

In the Emissions Menu of input.geos we currently have:

%%% EMISSIONS MENU %%%  :
HEMCO Input file        : HEMCO_Config.rc
Switches for UCX        :---
 => Use CH4 emissions?  : F
 => Set init. strat. H2O: T

The switch for Set init. strat. H2O has been a source of user confusion because this option should always be turned off for runs other than an initial simulation but often users forget (or don't know) to update this for subsequent runs. We will remove this switch and if users would like to change the initial concentrations of H2O for their simulations, they should do so by manipulating the initial conditions (i.e. restart file) manually.

The switch for Use CH4 emissions is not needed. We should rely completely on settings in HEMCO_Config.rc for emissions. This switch enables calls to routine EMISSCH4 in global_ch4_mod.F90 but that routine should only be used for CH4-only simulations, and is also only needed in those simulations for perturbing emissions in the case of analytical inversions. Ideally this would also be done in HEMCO_Config.rc in the future.

Finally, the setting for HEMCO Input file : HEMCO_Config.rc should really not be changed. We don't allow users to modify the filenames for other input files (input.geos, ExtData.rc, HISTORY.rc), so we should also have HEMCO_Config.rc as the standard name for the HEMCO configuration file. Users can always have multiple versions of this file with different names if they want to evaluate and save different emissions settings.

[msulprizio]

This update is now pushed to the dev/13.0.0-final branch.