* Allow `conn.fetch(" ... ")` to be called where `conn` is an owned Connection
* Executor::fetch -> RefExecutor::fetch_by_ref
* Executor::fetch_by_ref -> Executor::fetch
* Move `Connection::describe` to `Executor::describe`
* `Transaction` is no longer a `Connection`
* `Connection` has `Executor` as a super-trait again which greatly simplifies bounds
* Intending to use in a new Row type to check types at runtime for
dynamic queries and to guard against schema changes
* Hoping the query! macro can utilize this to allow accepting N
rust types for 1 sql type and returning N rust types for 1 sql
type.
