merge IntervalsModel into CovidAlertVaccinationModel, dependecies are too tight to manage as too packages easily

removed LTC/HCW stuff, contact generation needs fixing, use bytearrays instead of bitarrays for weights

Seperated Zeroweighteddistributions into its own package, implemented WS/Rest functions, although fitting doesn't work too well yet

more performance improvements to network generation, contact distributions now depend on google mobility data