Note: this will only implement changes from SPEC-1141 (830715c), which did not specify how startAfter should be used for resuming. That functionality will be deferred to PHPLIB-411, which corresponds to SPEC-1122 (b00dbe8).
has to be done before
PHPLIB-411Support postBatchResumeToken in change streams
is depended on by
DRIVERS-544Support 'startAfter' option to the $changeStream stage