Fix #1283: Warn and handle missing FORMAT fields in snp_calls_to_vcf()#1284

Yashsingh045 wants to merge 1 commit intomalariagen:mastermalariagen/malariagen-data-python:masterfrom

Yashsingh045:GH1283-warn-missing-vcf-fieldsYashsingh045/malariagen-data-python:GH1283-warn-missing-vcf-fieldsCopy head branch name to clipboard