Improve performance when getting clinvar annotations for sample's variants

[tonydisera]

Improve performance when getting clinvar annotations for sample's variants

[tonydisera]

Solution:

1. Have s3 txt file containing number of variants per gene
2. Grab all clinvar variants for a gene ONLY when clinvar variant count is less than number of variants in sample. Otherwise, grab only clinvar variants for sample's variant (positions)

Also, get all Clinvar variants for union of variants from trio so that gene.iobio makes one trip to the server to get Clinvar variants for a gene rather than 3 (for a trio).