added distinct vaccination/infection stages, immunization delay, and univariate figures showing more useful results with these changes

new output plots, alert mechanic bug fixed and mechanic changed to give alerts if coin flips exceed notification_threshold

add univariate snensitivity plots, some output code, added the model size and length to parameter tuple. New output is in /CovidAlertVaccinationModel/plots/univariate

added tests to ZeroWeightedDistributions, removed vector rand function cause it was wrong, but we don't use it in the simulations anyway

app dynamics and opinion dynamics done, I think? people seem to rapidly switch opinions which is probably wrong

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