ddl(ticdc): add charset and collate to ddl event (#8723)

[ti-chi-bot]

This is an automated cherry-pick of #8723

What problem does this PR solve?

Issue Number: close #8568

What is changed and how it works?

• add charset and collation to the DDL event.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)

1. deploy 2 tidb clusters, as upstream and downstream.
2. create a changefeed
3. run the following SQL

set character_set_connection=utf8;

CREATE TABLE `t` (
  `pk` bigint(20) NOT NULL AUTO_INCREMENT,
  `j` json DEFAULT NULL,
  `i` int(11) DEFAULT NULL,
  `c` char(64) DEFAULT NULL,
  PRIMARY KEY (`pk`) /*T![clustered_index] CLUSTERED */
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin AUTO_INCREMENT=30001;

alter table t add index j((cast(j->'$.number[*]' as signed array))); 

show create table t;

4. both tidb clusters have the same output.

Questions

Will it cause performance regression or break compatibility?

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

Release note

`None`

[ti-chi-bot]

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[ti-chi-bot]

@ti-chi-bot: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
jenkins-ticdc/verify	1b92c10	link	true	/test verify

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