Added supplier for DataLoaderDispatcherInstrumentationOptions (fix #98)

[oliemansm]

@marshi
This allows you to configure the options you want to use when constructing a DataLoaderDispatcherInstrumentation:

GraphQLQueryInvoker.newBuilder().
    .withDataLoaderDispatcherInstrumentationOptions(DataLoaderDispatcherInstrumentationOptions.newOptions().includeStatistics(true))
    .build();

These options are then used here:

protected Instrumentation getInstrumentation(Object context) {
   if (context instanceof GraphQLContext) {
       return ((GraphQLContext) context).getDataLoaderRegistry()
                .map(registry -> {
                    List<Instrumentation> instrumentations = new ArrayList<>();
                   instrumentations.add(getInstrumentation.get());
                   instrumentations.add(new DataLoaderDispatcherInstrumentation(registry, dataLoaderDispatcherInstrumentationOptionsSupplier.get()));
                    return new ChainedInstrumentation(instrumentations);
                })
               .map(Instrumentation.class::cast)
               .orElse(getInstrumentation.get());
   }
   return getInstrumentation.get();
}

[marshi]

this is exactly what i want to do.
thank you for great enhancement .