Add multi-language AST-pattern scanning support

- Introduced `patterns` module with language-specific vulnerability patterns.
- Added `query_cache` utility for caching compiled queries.
- Expanded `scan.rs` to support scanning multiple languages dynamically.
- Updated `Cargo.toml` with additional tree-sitter dependencies.
- Added severity filtering to `ScannerConfig` for better configuration.

src/main.rs

@@ -3,6 +3,7 @@ mod commands;
 mod utils;
 mod walk;
 mod database;
+mod patterns;
 
 use crate::utils::Config;
 use cli::Cli;