Support NA -> AA translation

[bovee]

This is a fairly basic bioinformatics function that we should probably add. Questions are:

• Which translation tables should we add and how should they be selected?
• Where should this funcationality be located? We probably need to clean up the Sequence processing API a little anyhow.

[luizirber]

This is the alphabet that mash supports: https://github.com/marbl/Mash/blob/03b28ed82edaaadb649517d5aa6820a7dc54e882/src/mash/Sketch.h#L27

and this is the translation table used in sourmash: https://github.com/dib-lab/sourmash/blob/bcbe958a859621f49e930dbf02d7ec42bda43945/src/sketch/minhash.rs#L613

[bovee]

Thanks @luizirber! I think those will be handy references.

I think the big two questions for me are how many translation tables do we want to support out of NCBI's list (https://www.ncbi.nlm.nih.gov/Taxonomy/Utils/wprintgc.cgi) and do we want to support all the IUPAC codes too (maybe yes? this is kind of a pain though).