Add CHM13 genome

[serge-p7v]

I also had to make gaps URL nullable because the new version of human genome doesn't have any gaps.

[serge-p7v]

Unfortunately, there are 124 warnings in the log such as:
2023-04-05 15:42:24,732 WARN [main] o.j.b.g.GtfReader [Ensembl.kt:337] Cannot detect UTR3 5' end for CHM13_T0140831. Not enough space for STOP codon only 1 bp available in exons after CDS 3' end.

That might be due to the problems in GTF file. The related issues are:
marbl/CHM13#52
ComparativeGenomicsToolkit/Comparative-Annotation-Toolkit#285

[iromeo]

I think it will be useful to AnnotationsConfigLoaderTest.parseYaml() to ensure that the genome with missing gap information can be successfully loaded from the YAML config. I suggest just updating test_annotations.yaml with config close to CHM13 genome.

[serge-p7v]

Thank you! I've just added the hs1 to test_annotations.yaml and updated the test.