Prevent arguments to bind from going out of scope during timed-out binds

Timeout testing in SERVER-58852 has revealed that certain arguments to bind sometimes go out of scope when a long hang is inserted before performing the network call. This is a concern because all arguments that are passed into any function that performs network calls to an LDAP server should remain in scope irrespective of how long the function takes to complete. More information provided in the dev-only comment below.