Customize annotation display

[9999years]

Annotations are currently always displayed with show, which leads to clumsy output, especially if the annotation is a JSON object or similar:

https://github.com/parsonsmatt/annotated-exception/blob/41731562c73d17f36fb22e0ede681bbced2abc3a/src/Control/Exception/Annotated.hs#L156

Being able to override how exceptions are displayed would make it possible to render annotations nicely in more cases.