Description
In many places we now use enumerations (resolution strategies, symbolic operators, ...). While these provide easier exhaustive checks (e.g. switch statements), they limit the extensibility of LiSA. For instance, if one was to define a custom symbolic operator for a specific construct, having an enumeration requires to recompile LiSA to add it. Instead, if we switch to a class hierarchy defined on interfaces, the new operator can be added in the frontend by making it implement the required interfaces.