fix(events): TypeScript linting errors
fix(events): TypeScript linting errors

Using a question mark and providing a default value are the same thing. In-fact, this will trigger a TypeScript compile error of: error TS1015: Parameter cannot have question mark and initializer. -- The fix is to remove the question mark.

aurelia-ui-toolkits/aurelia-kendoui-plugin,aurelia-ui-toolkits/aurelia-kendoui-plugin,aurelia-ui-toolkits/aurelia-kendoui-bridge,aurelia-ui-toolkits/aurelia-kendoui-bridge