enhancement for "distinct" values in return statement

[shaharido1]

Hello,
A possible nice simple enhancement could be adding a "distinct" flag to the query. Something along this lines ->

https://github.com/threatify/arango-orm/blob/master/arango_orm/query.py#L251

        if self.is_distinct:
            return_index = aql.find("RETURN") + len("RETURN")
            print(aql)
            aql = aql[:return_index] + ' distinct(' + aql[return_index:]
            aql = aql + ")"

What do you think?

[kashifpk]

@shaharido1 - yes that makes sense. I'll include it in upcoming release.