fix logic to properly read input files by handling inputs that support multiple inputs with labels (used by GridDiag and UserScript wrappers) and typical inputs (all other wrappers). Prior to this change only input templates that have the FCST or OBS identifier were read properly via get_input_templates

fix logic to properly read input files by handling inputs that support multiple inputs with labels (used by GridDiag and UserScript wrappers) and typical inputs (all other wrappers). Prior to this change only input templates that have the FCST or OBS identifier were read properly via get_input_templates #5183