binlog: use node.Restore() to add TiDB-specified feature comments

[bb7133]

Enhancement

For TiDB-specified features like AUTO_RANDOM attributes, we comment them in TiDB-specified comments for binlog-based replication(deprecated, but still used by some customers) and TiCDC.

After pingcap/tiflow#3755, TiCDC used the node.Restore() method from parser to add the comments in pingcap/tiflow#3845, rather than the regex-based way for binlog.

Although using node.Restore() is slower than regex, IMO it's better to adopt node.Restore() to replace the regex implementation for basically 2 reasons:

• It is robust.
• It makes consistent results for both binlog and TiCDC replications.