Client-side parsing of statement code for special commands [SET, USE, etc]

This needs to be done for the language server features as well as any statement submit/run actions.
We want to parse the document in case of multiple commands, SET/USE commands, etc. DTSQL Parser??

✏️ We can reference the Workspaces UI utils files for how they are parsing statements, as well as the Flink team's document titled "Specification for SQL Clients"