Option to input & subset multi-sample BED in VaPoR (+ womtool fixes)

[epiercehoffman]

Updates

• Option to provide multi-sample instead of single-sample BED file for VaPoR input - users should then provide a sample ID to extract from the multi-sample BED file before the VaPoR tool is invoked. Allows users to use the cohort-wide BED file produced by MainVcfQc directly
• Style edits in VaPoR WDLs: spacing, make VCF / BED file required in file-specific WDLs
• Various womtool fixes to get validation to run with validation script (tested with womtool-80)

Testing

• Womtool validation of all WDLs and JSONs
• Tested VaPoR on Terra with multi-sample BED file + sample ID to extract
• Tested VaPoR on Terra with single-sample BED file - output identical to previous master