Investigate support for generics in Go 1.18

[mrnugget]

We should check if generics cause lsif-go to crash by testing it against existing package with generics.

[Strum355]

First round of investigation:

lsif-go does not panic on a codebase with generics, and the LSIF upload is succesful.
And thats mostly where the good parts end.

The hover is mostly useless, and codeintel for the type and most of the rest of the file are not precise at all

[mrnugget]

Thanks! Do you plan to do another "round of investigation" in this iteration? If so, feel free to re-open, because I'm closing this now since we got what we wanted.