branch-2.1: [feat](debugpoint) add a backup block debug point for ccr test #50380

[github-actions]

Cherry-picked from #50380

[Thearas]

Thank you for your contribution to Apache Doris.
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Please clearly describe your PR:

1. What problem was fixed (it's best to include specific error reporting information). How it was fixed.
2. Which behaviors were modified. What was the previous behavior, what is it now, why was it modified, and what possible impacts might there be.
3. What features were added. Why was this function added?
4. Which code was refactored and why was this part of the code refactored?
5. Which functions were optimized and what is the difference before and after the optimization?

[Thearas]

run buildall

[koarz]

run p0

[koarz]

run p0

[koarz]

run p0

[koarz]

run p0

[github-actions]

We're closing this PR because it hasn't been updated in a while.
This isn't a judgement on the merit of the PR in any way. It's just a way of keeping the PR queue manageable.
If you'd like to revive this PR, please reopen it and feel free a maintainer to remove the Stale tag!