Rewrite AlleleFilter.filter_alleles/filter_analysis to take in filter config object rather than id
Background
For testing new filter configs it shouldn't be necessary to deposit them to the database. However, with the signature of AlleleFilter.filter_alleles/filter_analysis it's not possible to use these functions without a filter config id.
Implementation
Move most of the code out of filter_alleles/filter_analysis into functions taking filter config object rather than id. The callees of these functions can be kept untouched, but with an "inbetween" function, we can utilize this when testing filter configs that are not in the database.