Reground outdated mouse/rat gene names

[bgyori]

During the latest reprocessing of the large corpus, I finally implemented turning the RGD and MGI gene names into proper IDs (previously, we just used these names as IDs which was obviously invalid), however, I found that many gene names used here are outdated. Presumably, by applying proper grounding (e.g., via Gilda with some extensions) we could get "refreshed", mouse- or rat-specific groundings for these genes to improve downstream use. One solution would be to make these replacements programmatically at the level of the BEL script. @cthoyt do you think that's a good idea or is there already a better way of doing this in place somewhere?