Add ClinGen Allele ID (CA#) to GREGoR report and variant metadata

[stephditroia]

Is your feature request related to a problem? Please describe.
We want to list ClinGen Allele IDs (CA#) for each variant on the variant metadata page and in the GREGoR report.

Describe the solution you'd like

1. Variant metadata: Add a ClinGen allele ID column to the Variant Metadata page and populate with each variant's CA#. This column was recently replaced by 'Clinvar allele ID': #4007
   Fine to replace Clinvar allele ID in the variant metadata if we don't want to keep both.

2. GREGoR report: Populate the ClinGen_allele_ID column in the genetic_findings table with the appropriate variant CA#. Leave column blank with CA# not available. GREGoR data model V1.5 mapping

[hanars]

We should also add this to the regular saved variant download/ search results download

[hanars]

This has been added