Add genetic code nodes

[rbaldwin-bugseq]

Added an optional arg to from_ncbi to add genetic_code to TaxonomyNode object

[audy]

@rbaldwin-bugseq can you tell me more about the use-case this solves? Accurately regenerating a full NCBI taxdump from a Taxonomy object feels a little out of scope and would require a more changes (E.g., adding more fields, loading non-"scientific name" names.dmp)

[rbaldwin-bugseq]

@rbaldwin-bugseq can you tell me more about the use-case this solves? Accurately regenerating a full NCBI taxdump from a Taxonomy object feels a little out of scope and would require a more changes (E.g., adding more fields, loading non-"scientific name" names.dmp)

my issue is that the dmp files output by this lib were not compatible with other bioinformatics software due to missing fields. in my case, it was the genetic code, so i just wanted to add it. Also adding the genebank common name would be useful. What, if anything, can be done to get these attributes added to the TaxonomyNode object ? Thank You.

[audy]

@rbaldwin-bugseq having full NCBI taxonomy + metadata support would be generally useful. However, this PR adds only the part needed for a specific downstream tool.

For full support, I think the following is needed:

1. Support for non-scientific names. This would be really useful (E.g., looking up taxa by synonym)
2. Support for general metadata about nodes (which could be used to store the genetic code and other NCBI-specific fields)
3. There are some open questions about interoperability with other formats (E.g., what happens to the other names/metadata when serializing to Newick?)

Closing this as out of scope for now -- full NCBI taxonomy support is something we'd like to tackle more holistically. Happy to revisit as a larger effort.