Add --ref_genes_file option to Homologs

[khiron]

Command alignments has an option --ref_genes_file which is a path to a .tsv file containing a stableid header

It would be useful to have a similar option in homologs so we can use the dump-genes command on a species (eg: human) and then use the resulting file subselect genes on a specific location (eg: Chromosome 1) and then use that to subsample homologs