Make query parameter name style configurable

[skykanin]

It would be nice for our use case to be able to configure the query parameter names so that we can choose if the names are camelCased, snake_cased or kebab-cased, i.e. sort_by instead of sortBy. These names are currently hardcoded, but this seems like it would be a useful feature to have in general so I thought I might contribute such a change. Afaict the only query parameter name this would apply to at the moment is "sortBy" as it's the only two word query parameter name. Would this an acceptable change to contribute to servant-util?

[Martoon-00]

Sounds like a fair concern, your PR would be welcome!