swap out u_pep_id names for older pep_id names to improve AVARDA speed

prepare_avarda_names(data, annotations = NULL, metadata_path = NULL,
  replacement_column = "pep_id")

Arguments

data	Phiplist of data to modify.
annotations	Phiplist of annotation files. Don't use with metadata_path param.
metadata_path	Metadata directory. Don't use with annotations param.
replacement_column	Column of metadata with which to replace current first column of data.