[v18.x backport] test_runner: introduces a new MockTimers API
Backport of https://github.com/nodejs/node/pull/47775
cc/ @ruyadorno @nodejs/test_runner
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Backport of https://github.com/nodejs/node/pull/47775
cc/ @ruyadorno @nodejs/test_runner