release-22.1: changefeedccl: support end time option for changefeeds

https://github.com/cockroachdb/cockroach/pull/78381 --- Release note (enterprise change): Allow users to provide an end time for changefeeds through the 'end_time' option. When this option is provided, the changefeed will run until it has reached the end time, and then the changefeed job will end with a successful status code. Furthermore, we now provide an 'initial_scan_only' option. When this option is set, the changefeed job will end with a successful status code immediately after the initial scan completed. Release Justification: This feature is low danger, yet highly desired from users.