**Is your feature request related to a problem or challenge? Please describe what you are trying to do.** Add support for Postgres SIMILAR TO syntax. https://www.postgresql.org/docs/current/functions-matching.html#FUNCTIONS-SIMILARTO-REGEXP **Describe the solution you'd like** Add support for Postgres SIMILAR TO syntax **Describe alternatives you've considered** None **Additional context** Depends on https://github.com/sqlparser-rs/sqlparser-rs/pull/569