[Feature Request] Log and drop signals that pass the wrong number of arguments

[cretz]

Describe the solution you'd like

In #349 we now drop signals whose arguments are of the wrong type. But we still fail the workflow task if the arity is off, e.g. with Python exceptions like "missing 1 required positional argument". Try to make sure there is one argument for every required parameter and no more than accepted (varargs notwithstanding). May be easiest to have a min/max param count on the _SignalDefinition and just check against that.