Notify user when the progress gap between the CDC source and the upstream DB is relatively large

[StrikeW]

Is your feature request related to a problem? Please describe.

When the progress gap between the CDC source and the upstream DB is relatively large, the kernel should notify the users, for example print a warn log or report on the grafana dashboard.
Right now it is silent and can only be sensed by querying the MV.

Describe the solution you'd like

No response

Describe alternatives you've considered

No response

Additional context

No response

[github-actions]

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