There pains of using a set as the aggregation of rules overweight the
small advantage. While it would make detecting similar rules faster, the
use of a collection type not inherently supporting by JSON brings some
issues in the serialization.
Due to the use of the dataclasses mixin on the SQLAlchemy types, a
back_populates creates a RecursiveError when comparing two types. This
occurs because the dataclass will overwrite the __eq__ operator, and it
doesn't know when to stop comparing relationships.
Removing the dataclasses isn't the best approach, since then __init__,
__eq__ and __repr__ methods would have to be added to all types. Thus
the solution was to remove the relationship on the child (on a
one-to-one relationship) from the __eq__ operation, with the use of the
compare parameter.
Took the opportunity to define more logical __init__ methods on the
`Rule` and child classes.
Also revised the parameter options on some DB types.
