GoRule57 filter lines by provided_by

[dustine32]

For the MOD imports project we need to port over the ability to filter for only lines with particular Provided_by values (MGI for the MGI GPAD, WB for the WB GPAD). Basically, we want to filter out all lines that are not from the MOD (e.g. UniProt, ARUK-UCL, SynGO). This was originally implemented for gocamgen: https://github.com/geneontology/gocamgen/issues/30

Since we already have a filter_out section in the go-site dataset YAML files for each group, we can specify what to filter for with a new filter_for or filter_in section?

filter_for:
  provided_by:
    - MGI

Hopefully, this doesn't over-complicate things.

Tagging @dougli1sqrd