Add implementation for the MockConsumer, previously unexisting, for fetching offsets based on provided timestamps.
The unit test case was improved to include the testing of the fetching offsets based on timestamps. ### Committer Checklist (excluded from commit message) - [ x ] Verify design and implementation - [ ] Verify test coverage and CI build status - [ x ] Verify documentation (including upgrade notes) [ Full content available at: https://github.com/apache/kafka/pull/5561 ] This message was relayed via gitbox.apache.org for [email protected]
