Optimize the handling of references when consuming data

[stof]

The method call to characterReference in all consumeData calls is costly.

Inlining it is quite easy, and allows avoiding reading twice the current token when there is no reference at this point.

Here is the effect on the benchmark included in this repo.

Before:
Loading: 127.32289552689
Writing: 37.346167564392

After:
Loading: 115.40209054947
Writing: 37.080278396606

That's a 9% improvement on the loading time.

[goetas]

Makes sense. Thanks