feat: add flexible nonce parameter support

- Add nonce_account and current_nonce to trade parameters
- Remove hardcoded NonceCache dependency from nonce_manager
- Update examples and documentation for new nonce usage
- Fix nonce documentation errors and improve clarity

examples/pumpfun_sniper_trading/src/main.rs

@@ -105,6 +105,8 @@ async fn pumpfun_sniper_trade_with_shreds(trade_info: PumpFunTradeEvent) -> AnyR
         close_wsol_ata: true,
         create_mint_ata: true,
         open_seed_optimize: false,
+        nonce_account: None,
+        current_nonce: None,
     };
     client.buy(buy_params).await?;
 
@@ -132,6 +134,8 @@ async fn pumpfun_sniper_trade_with_shreds(trade_info: PumpFunTradeEvent) -> AnyR
         create_wsol_ata: true,
         close_wsol_ata: true,
         open_seed_optimize: false,
+        nonce_account: None,
+        current_nonce: None,
     };
     client.sell(sell_params).await?;