Allow users to pass literal strings instead of enum values everywhere #98
Description
See discussion here
A really easy thing to do first would be to just allow values in type Literal["DEFAULT", "LAPLACE", "GAUSSIAN"] in addition to CountMechanism in QueryBuilder.count (and same for other aggregations), and convert the string to the corresponding enum value behind the scenes. This would greatly simplify client code and tests.
Afterwards we might even consider deprecating enum values completely.