chore: Reorganize examples and interop crates (#180)

* chore: Reorganize examples and interop crates

* fix interop tests

examples/src/load_balance/client.rs

@@ -0,0 +1,29 @@
+pub mod pb {
+    tonic::include_proto!("grpc.examples.echo");
+}
+
+use pb::{echo_client::EchoClient, EchoRequest};
+use tonic::transport::Channel;
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let endpoints = ["http://[::1]:50051", "http://[::1]:50052"]
+        .into_iter()
+        .map(|a| Channel::from_static(a));
+
+    let channel = Channel::balance_list(endpoints);
+
+    let mut client = EchoClient::new(channel);
+
+    for _ in 0..12usize {
+        let request = tonic::Request::new(EchoRequest {
+            message: "hello".into(),
+        });
+
+        let response = client.unary_echo(request).await?;
+
+        println!("RESPONSE={:?}", response);
+    }
+
+    Ok(())
+}