Optimize TpuConnection and its implementations and refactor connection-cache to not use dyn in order to enable those changes (#23877)

streamer/src/sendmmsg.rs

@@ -8,6 +8,7 @@ use {
     std::os::unix::io::AsRawFd,
 };
 use {
+    solana_sdk::transport::TransportError,
     std::{
         borrow::Borrow,
         io,
@@ -24,6 +25,12 @@ pub enum SendPktsError {
     IoError(io::Error, usize),
 }
 
+impl From<SendPktsError> for TransportError {
+    fn from(err: SendPktsError) -> Self {
+        Self::Custom(format!("{:?}", err))
+    }
+}
+
 #[cfg(not(target_os = "linux"))]
 pub fn batch_send<S, T>(sock: &UdpSocket, packets: &[(T, S)]) -> Result<(), SendPktsError>
 where