LongReads: Improve GSvar SV filter

[leonschuetz]

• [ ] quality of Sniffles is capped to 60 -> adjust threshold
• [x] split INFO fields in seperate columns:
  • [x] GT
  • [x] supporting reads
  • [ ] coverage of ref/alt reads
• [ ] add filters:
  • [ ] phasing (type, block)
  • [x] Support reads
  • [x] Coverage
  • [x] AF
  • [x] Genotype

megSAP/ngs-bits:

• [x] add phasing info like SNV/INDELs

NGSDAnnotateSV:

• [x] calculate Breakpoint density per processing system

[leonschuetz]

• [x] compHet filter on phasing blocks

[leonschuetz]

• [x] add tests