Test TiCDC replication with Aliyun RDS MySQL

Feature Request

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

Recently we get some feedback from users that they fail to create changefeed with aliyun rds MySQL as downstream sink. The error from TiCDC is

[CDC:ErrMySQLQueryError]Error 1298: Unknown or incorrect time zone: 'Asia/Shanghai'

Query for mysql.time_zone_name returns empty result

mysql root@127.0.0.1:(none)> select * from mysql.time_zone_name;
+------+--------------+
| Name | Time_zone_id |
+------+--------------+
0 rows in set

Seems the available timezone variable is CST only

mysql root@127.0.0.1:(none)> show variables like '%time_zone%';
+------------------+--------+
| Variable_name    | Value  |
+------------------+--------+
| system_time_zone | UTC    |
| time_zone        | SYSTEM |
+------------------+--------+
2 rows in set

Describe the feature you'd like:

• 1. Support to pass timezone directly in sink uri, the timezone string literal will be passed to sink DSN directly. https://github.com/pingcap/ticdc/pull/1030
• 2. Test whether CST or empty timezone works in aliyun rds mysql.
• 3. Test whether we can insert more timezone information into aliyun mysql tables.
• 4. After step1-3 finished, provide a completed replication guidance about replicating from TiDB to aliyun rds MySQL

Describe alternatives you've considered:

If we have more time, we could also have a test other cloud service suppliers, such as AWS RDS, AWS Aurora, etc.