Replaces the module of the request that matches resourceRegExp with an empty module.
If the second argument source is specified, it will be used as the source of the new module. If the source is a function, it will be called with the request and the result will be used as the source of the module.
new EmptyModulePlugin(resourceRegExp)
new EmptyModulePlugin(resourceRegExp, '/* was replaced with empty module */')
new EmptyModulePlugin(resourceRegExp, (request) => '/* ' + request + ' was ignored */')