snowflake column identifier for copy into / query data staged in files

[pawel-big-lebowski]

According to documentation, Snowflake allows:

• query data staged in files with an identifier of a form [<alias>.]$<file_col_num>[.<element>]
• copy into table with an column identifier containing $ character like select t.$1,t.$2,t.$3 from @~/datafile.csv.gz t;

Although the feature seems to be snowflake specific, it cannot be implemented within snowflake dialect. It's because tokens starting with $ character are tokenized into Token::Placeholder. That's why parser's change is required.

Initial OpenLineage project issue: OpenLineage/OpenLineage#814