QueryMapper should be configurable for MongoTemplate [DATAMONGO-1966]

Nick Balkissoon opened DATAMONGO-1966 and commented

We should allow QueryMapper to be configurable if someone wants to extend the functionality of QueryMapper.  I have a use case where I am transforming data before persisting it to Mongo, and so when I'm querying I'd like to do the same transformation to queries so that our data transformation is transparent to anyone querying the db.  So QueryMapper should be exposed for DI or shouldn't be final so we can override the default if we extend MongoTemplate.

this.queryMapper = new QueryMapper(this.mongoConverter);

Curious to hear people's thoughts on this

No further details from DATAMONGO-1966