Clean up template namelist files for the forecast model (for various …

…CCPP physics suites). Just cosmetic changes; results should not be affected. Details below.

* Change indentation so all template files use the same.
* Remove blank lines.
* Remove extra space at end of lines.
* Remove double-comment characters (keep only one comment character).
* Remove repeated namelist variable entries.
* Move comment character in commented-out lines to the first column in the line.
* In input.nml.FV3_GFS_2017_gfdlmp, for consistency with the other template namelist files, change the hard-coded entry for ccpp_suite to be a placeholder.
* In input.nml.FV3_GSD_SAR, bug fix: Add the "/" character at the end of the "namsfc" namelist.