Test genome only download runs from NCBI DOWNLOAD

[chriswyatt1]

I think it will be possible to run the pipeline potentially with Genbank accessions (GCA.......).

At the moment, either you supply the genome + annotation manually, or use NCBI DOWNLOAD on a Refseq ID (GCF......) to get the genome and annotation automatically.

GCA accensions often only link to a genome wihtout a annotation in GFF, but these people may want to run.

We should test if this is a possible feature to add