Consider names Aus(Bus) L. from botanical perspective

[dimus]

created by @dimus at https://gitlab.com/gogna/gnparser/-/issues/58

There is a significant number of names in Botany that have Aus (Bus) Cus format, where Bus seem to be an original author of a clade, and Cus is the later author who changed the meaning of the clade. Currently parser treats such names as Genus (Subgenus) SubgenusAuthor, resulting on creation of nonexistant subgenera records. It seems there is less harm to consider such names from botanical perspective and think of them as Genus (OrigAuthor) SecondaryAuthor. It seems we need a dictionary of authors to treat such cases correctly and make distinction between botanical authors and zoological subgenera.