add list of all names to Taxon

Hi Antonio, not sure if you will find this useful, but I needed a more complete list of names for a taxon in addition to the scientific name. I didn't update the docs yet. If you'd consider merging this, I can also add something to the documentation. ``` (Pdb) taxopy.Taxon(9606, ncbi_taxonomy).name 'Homo sapiens' (Pdb) taxopy.Taxon(9606, ncbi_taxonomy).names [('authority', 'Homo sapiens Linnaeus, 1758'), ('scientific name', 'Homo sapiens'), ('genbank common name', 'human')] (Pdb) taxopy.Taxon(10090, ncbi_taxonomy).names [('genbank common name', 'house mouse'), ('includes', 'LK3 transgenic mice'), ('common name', 'mouse'), ('authority', 'Mus musculus Linnaeus, 1758'), ('scientific name', 'Mus musculus'), ('includes', 'Mus sp. 129SV'), ('includes', 'nude mice'), ('includes', 'transgenic mice')] (Pdb) taxopy.Taxon(9823, ncbi_taxonomy).names [('genbank common name', 'pig'), ('common name', 'pigs'), ('authority', 'Sus scrofa Linnaeus, 1758'), ('scientific name', 'Sus scrofa'), ('common name', 'swine'), ('common name', 'wild boar')] ``` <!-- Generated by sourcery-ai[bot]: start summary --> ## Summary by Sourcery Introduce a new feature to the `Taxon` class that allows retrieval of a comprehensive list of names for a taxon, enhancing the existing functionality by including various name types such as scientific, common, and authority names. New Features: - Add a new property `names` to the `Taxon` class that provides a list of all names associated with a taxon, including scientific, common, and authority names. Enhancements: - Extend the `_import_names` method to populate a new dictionary `taxid2names` that stores all names associated with each taxon ID. <!-- Generated by sourcery-ai[bot]: end summary -->