Class SHiP::CovfieFieldSource: Reads .cvf files; see loadCovfieField.
Member SHiP::loadCovfieField (std::string const &cvf_path): .cvf is covfie's internal serialisation and changes with covfie versions. Store maps in the SHiP field-map format (docs/field_map_format.md) and load them with FieldMapSource from the MapIO component instead. .cvf support will be removed in a later release.