Enable ConstructorThrow SpotBugs detector

Spotbugs was upgraded to 4.9.3.0 in #5623 , but the ConstructorThrow detector was disabled because fixing the issues would take a refactoring of classes that throw Exceptions from their constructors. Doing the refactoring in a bugfix release didn't make much sense. This task is to enable the detector and refactor the classes to not throw Exceptions from their constructors.