Fix on checking for columns of functional IDs

KEGGCharter was only looking for KEGG IDs, KOs and EC numbers columns to check if some functional IDs column was inputted.

This would make it exit with error if only a column with COG IDs was inputted.

Now it also looks for COGs columns, and accepts to only input a COG IDs column.

Also am trying to understand with it doesn't find cog2ko.tsv.