refactor: convert EventParser to static methods and optimize caching

- Replace instance-based EventParser with static method design
  - Introduce ParserCache module for protocol config caching
  - Simplify EventProcessor to pure functional handlers
  - Optimize metrics: remove min/max tracking, keep last + avg only
  - Reduce atomic operations in hot path for better performance

src/streaming/event_parser/core/mod.rs

@@ -1,7 +1,12 @@
 pub mod account_event_parser;
 pub mod common_event_parser;
 pub mod global_state;
+pub mod parser_cache;
 pub mod traits;
 pub use traits::UnifiedEvent;
+pub use parser_cache::{
+    AccountEventParseConfig, AccountEventParserFn, GenericEventParseConfig,
+    InnerInstructionEventParser, InstructionEventParser, get_account_configs,
+};
 
 pub mod event_parser;