Hide "template" metadata fields

[LucaCinquini]

Who: Karl

The following fields are not important to users and should be hidden in the dataset and file metadata display:

dataset_id_template_ = CMIP6.%(activity_drs)s.%(institution_id)s.%(source_id)s.%(experiment_id)s.%(member_id)s.%(table_id)s.%(variable_id)s.%(grid_label)s 

directory_format_template_ = %(root)s/%(mip_era)s/%(activity_drs)s/%(institution_id)s/%(source_id)s/%(experiment_id)s/%(member_id)s/%(table_id)s/%(variable_id)s/%(grid_label)s/%(version)s