variant-database/vdb: Release version 2.0

Improved list functionality Results of most list commands can be assigned to a variable These lists can be saved to a file Some commands can be applied to lists Ability to use an item from a list (e.g. a pattern) in certain commands quiet mode added for commands acting on lists Dataset loading is now multithreaded maxMutationsInFreqList setting added Ability to load clusters from Pango definition file Updated WHO variants