Show user genomes with missing hmm-source

[mschecht]

This PR gives anvi-script-gen-hmm-hits-matrix-across-genomes a more informative error that tells users which genomes do not contain the hmm-source of interest. In the cases of a large external-genomes.txt, this will allow the user to quickly assess which genomes require the anvi-run-hmms.

You can reproduce the upgrade with the metagenomics-full component tests. (Comment out most of the component test script to isolate this test.)

anvi-self-test --suite metagenomics-full --output-dir metagenomics-full --force-overwrite

cd metagenomics-full

anvi-delete-hmms -c E_faecalis_6563.db --hmm-source Bacteria_71

$ anvi-script-gen-hmm-hits-matrix-across-genomes -o TEST/GENOME_MATRIX.txt 
                                               -e external-genomes.txt 
                                               --hmm-source Bacteria_71

Config Error: Bad news. An HMM source you requested (Bacteria_71) is missing from some of your
              contigs databases :/ Here is the list: E_faecalis_6563

[meren]

Thanks for this, Matt!