Enable ALGs to be one-species or two-species

[conchoecia]

Sometimes manuscripts define LGs to be based on the genes of one species, like the CLGs in Simakov et al 2020. The ALG database functionality needs to be changed to allow for LGs based on single species. Currently two species are required due to the limitations of the HMM-building step. In these cases the search would be performed with diamond blastp instead of hmmer. This will speed up the addition of the CLG database after one user referenced this database for #27.