refactored L::Utils::get_yaml to only require args needed for construction of path/to/yaml_dir/filename to remove duplication from components requiring a get_yaml_file() method (Controllers, Model & ScriptHelpers)

moved diagnosis_confirmation_required from Local::Utils to new Local::Role::DiagnosisConfirm - didn't belong in Utils class, and function now needs to access LIMS config to load yaml files dir dynamically depending on CENTRE env param