scheduler(ticdc): add splitter interface

[overvenus]

What problem does this PR solve?

Issue Number: ref #7720

What is changed and how it works?

Add splitter interface to support splitting span by region written keys in #8496

Check List

Tests

• Unit test

Questions

Will it cause performance regression or break compatibility?

No.

Do you need to update user documentation, design documentation or monitoring documentation?

No.

Release note

None

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• 3AceShowHand

To complete the pull request process, please ask the reviewers in the list to review by filling /cc @reviewer in the comment.
After your PR has acquired the required number of LGTMs, you can assign this pull request to the committer in the list by filling /assign @committer in the comment to help you merge this pull request.

The full list of commands accepted by this bot can be found here.

Reviewer can indicate their review by submitting an approval review.
Reviewer can cancel approval by submitting a request changes review.

[overvenus]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: eba7841

[overvenus]

/run-integration-test

[overvenus]

/run-all-tests

[ti-chi-bot]

@overvenus: Your PR was out of date, I have automatically updated it for you.

At the same time I will also trigger all tests for you:

/run-all-tests

trigger some heavy tests which will not run always when PR updated.

If the CI test fails, you just re-trigger the test that failed and the bot will merge the PR for you after the CI passes.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

[overvenus]

/run-kafka-integration-test

[overvenus]

/run-kafka-integration-test