feat(proto): add generic proto reader

proto/src/reader/protoreader.rs

@@ -0,0 +1,22 @@
+use crate::reader::utils::AsyncPeek;
+use tokio::io::AsyncBufRead;
+
+pub struct ProtoReader<R>
+where
+    R: AsyncBufRead + AsyncPeek + Unpin + Send,
+{
+    pub(super) inner: R,
+    pub(super) msg_len_limit: i32,
+}
+
+impl<R> ProtoReader<R>
+where
+    R: AsyncBufRead + AsyncPeek + Unpin + Send,
+{
+    pub fn new(reader: R, msg_len_limit: i32) -> ProtoReader<R> {
+        ProtoReader {
+            inner: reader,
+            msg_len_limit,
+        }
+    }
+}