coord: Advance timelines when creating new obj

[jkosh44]

If an object is created with an initial read frontier that is larger than the current timestamp of the timeline that object belongs to, then we must advance that timeline to the frontier of that object. This commit updates the code to do that.

The alternative would be to wait until the timeline catches up to the object and then add the object to the timeline.

Fixes #14136

Motivation

This PR fixes a recognized bug.

Checklist

• [X] This PR has adequate test coverage / QA involvement has been duly considered.

• [ ] This PR evolves an existing $T ⇔ Proto$T mapping (possibly in a backwards-incompatible way) and therefore is tagged with a T-protobuf label.

• [ ] This PR includes the following user-facing behavior changes:

  • N/A

[benesch]

Linking in this Slack conversation for context: https://materializeinc.slack.com/archives/CMHDK0DK8/p1660073744743419?thread_ts=1660009902.062619&cid=CMHDK0DK8. It seems like we might instead want to be fixing the root cause, and turning this log message into a panic.