Variant prioritisation, cram compression

• Adds pre-DECIPHER variant prioritisation
  • Modifies extract_*_FAM_PRO_ID.py
• Adds post-DECIPHER variant prioritisation for trios
  • Uses DECIPHER_INTERNAL_IDs.txt from independent upload
• Had to refactor some of the scripts in bin/ to work with Nextflow
• Moves param defaults from main.nf to nextflow.config
• Splits Cram compression/decompression off into their own workflow
• Makes validation.nf less spammy
• Adds a bunch of documentaton of channel formats
• Makes test family IDs reflect reality better