"Known Partner" curation for `v` fusions

[acoffman]

For v Fusion partners, it may be useful to curate Genes that have appeared as the partner on either the feature or variant.

This could just be a hang off table like aliases, except constrained to known Genes. Would we want to track the frequency each gene appeared or which EIDs mentioned them, or is it strictly an "alias" style list of Genes?