feat: add rule to support ::regclass::oid cast

[sunng87]

this isn't a simple cast to data type, it translate a table name to oid. So we rewrite this cast to a subquery to find oid from pg_catalog.pg_class

[sunng87]

limitation:

1. postgres allows syntax like schema.table::regclass::oid convert schema.table to its oid directly. our current implementation only has table/pg_class support
2. in extended query, the client will send "table" quoted with double-quote as an identifier. we will need to unquote when parsing the text input. this has to be done in pgwire for a usable unquote function.
3. we can use parse_ident function on schema.table or table to unquote and parse the schema.table syntax. but there is another issue that datafusion doesn't support parameter type inference for scalarfunction, so parsing the parameter may fail.