QA of SIDER KGX ingest

[vdancik]

QA Resources:

• KGX Summary report: (sider_KGX_SUMMARY)
• RIG: (sider_rig.yaml)
• RIG Update PR: Enhance SIDER YAML with knowledge sources and explanation #292

Issues to consider / address for January updated release:

• . . .

Issues to consider longer term:

• Categories created by Node Normalizer
• Some background exploration suggested that SIDER provides qualitative frequency info about side effects (e.g. terms like 'very common', 'uncommon'). This seems like useful info we should consider pulling in.

Questions:

• . . .

[mbrush]

My review is done. All looks good with the exception of NN issues noted above, which will require a longer term fix.

• I did add some content to the RIG - take a quick peek at the changes in this PR and make sure you agree - then merge once you are done.