[FT-220] Sore job last status change time

Instead of prepared job run duration
Extended Variant tables with larger columns and extra tables

Some columns are enlarged (e.g. ref, alt, info and format) to enable
loading larger VCF files. Moreover, two tables are added to store population-
level data that is present in the VCF files (the info fields).
Merge branch 'FT-220'
Merge branch 'master' into gwas