OGM-273 DO NOT INCLUDE Method to get the entity from a tuple

`LoaderFromTupleTest` shows how to use it.
Note that the test fails for MongoDB because MongoDB does a maping between the logical id column and `_id`. The test does not take that into account.

We need to add a `GridDialect.getAllTuples(Consumer, EntityKeyMetadata...)`

That way the driver has access to the table as well as the id column names will be via the `EntityMetadataKey`. The related issue is https://hibernate.onjira.com/browse/OGM-151
The MongoDB driver will provide a specific snapshot that takes the EntityKeyMetadata info into account.

I think we can carry on in the mean time and fix OGM-151 in parallel.