Refactor SQL queries into centralized module

- Moved various SQL query strings from individual worker files into a new `sql.rs` module for better organization and reusability.
- Updated `events.rs`, `underground.rs`, and `weather.rs` to use the centralized SQL queries.
- Removed redundant query definitions from `events.rs`, `underground.rs`, and `weather.rs`.

src/worker/mod.rs

@@ -11,6 +11,7 @@ mod user_character;
 mod transport;
 mod weather;
 mod events;
+mod sql;
 
 pub use base::Worker;
 pub use crate::db::ConnectionPool;