Add support for PostgreSQL LOCK TABLE

[mjbshaw]

PostgreSQL 14 added LOCK. This implements parsing support for that statement. Beyond the added tests, the following minimum reproducible example demonstrate's sqlparser's current failure to parse this statement:

Cargo.toml:

[package]
name = "demo"
version = "0.1.0"
edition = "2024"

[workspace]

[dependencies]
sqlparser_patched = { package = "sqlparser", path = "path/to/mjbshaw/fork/datafusion-sqlparser-rs" }
sqlparser_published = { package = "sqlparser", version = "0.61.0" }

src/main.rs:

use sqlparser_patched::dialect::PostgreSqlDialect as PatchedPostgreSqlDialect;
use sqlparser_patched::parser::Parser as PatchedParser;
use sqlparser_published::dialect::PostgreSqlDialect as PublishedPostgreSqlDialect;
use sqlparser_published::parser::Parser as PublishedParser;

const SQL: &str = "LOCK TABLE public.widgets IN EXCLUSIVE MODE";

fn main() {
    match PublishedParser::parse_sql(&PublishedPostgreSqlDialect {}, SQL) {
        Ok(statements) => panic!(
            "expected published sqlparser 0.61.0 to reject `{SQL}`, but it parsed: {statements:?}"
        ),
        Err(error) => {
            println!("published sqlparser 0.61.0 failed as expected: {error}");
        }
    }

    let statements = PatchedParser::parse_sql(&PatchedPostgreSqlDialect {}, SQL)
        .expect("patched sqlparser should parse PostgreSQL LOCK TABLE");
    assert_eq!(statements.len(), 1, "expected exactly one statement");
    println!("patched sqlparser parsed successfully: {}", statements[0]);
}

Then run with cargo run.