Support upsert_many CRUD operation

[akudiyar]

Documentation:

• https://github.com/tarantool/crud#upsert-many

Implementation of this feature will require introducing a new type, which will combine tuple and tuple operation together, like it is in the tarantool/crud API. The current implementation of upsert operation is not completely correct: it allows to specify a tuple or a tuple operation separately without any checks for consistency, which doesn't correspond to the tarantool/crud API, although this invariant isn't clearly articulated there. Therefore, when implementing this feature we will have to introduce a breaking change in the UpsertProxyOperation API. Fortunately, we can leave the upsert() public method signatures as is, and just add the corresponding checks there; but the batch upsertMany operation variant will have to expose some kind of a tuple+operation container.

[dkasimovskiy]

Need to double check do we wont to implement this operatoin in the driver.