Adapt `proof_of_sql_parser::posql_time` to `sqlparser`

[iajoiner]

Background and Motivation

This issue is a subtask in https://github.com/spaceandtimelabs/sxt-proof-of-sql/issues/235. In short since we plan to add more SQL features we plan to switch to the sqlparser crate which is a feature-rich, no_std-compatible parser used by DataFusion, which is part of the Arrow ecosystem.

Right now we already have some code that can convert intermediate AST from proof-of-sql-parser we use to sqlparser AST. Now we need to systematically replace instances of proof-of-sql-parser constructs with their corresponding sqlparser ones.

Changes Required

• [ ] Adapt proof_of_sql_parser::posql_time to sqlparser

This task requires further breakdowns. Please make sure to post your plan here and discuss with @Dustin-Ray , @JayWhite2357 or I before starting your work.