ArangoDB FullCount option for pagination support

[sparkacus]

Would it be possible to support additional query params such as 'FullCount' ?

https://github.com/arangodb/go-driver/blob/v1.6.6/v2/arangodb/database_query.go#L83

This would be really useful for pagination purposes.

Currently I'm having to return the full dataset with every query to determine the count, and then chunking the results app side, but I'd prefer to use OFFSET & LIMIT to optimise the data transfer between the DB and APP