Context

The driver.Connection interface is returned by various functions with the x package, which is a pattern in conflict with the Go idiom of "accept interfaces, return structs" defined in the wiki: https://github.com/golang/go/wiki/CodeReviewComments#interfaces . And generally violates the robustness principle: https://en.m.wikipedia.org/wiki/Robustness_principle

Furthermore, this pattern makes migrating the description package to the internal package difficult since the connection interface has a dependency on the description package. 

Definition of done

We should centralize the connection object as a struct in a one-off package in the x/mongo/driver director. This was we can take an experimental subset of the server object as the description.

Pitfalls

Unknown