chore: Reorganize examples and interop crates (#180)

* chore: Reorganize examples and interop crates

* fix interop tests

examples/src/tls/client.rs

@@ -0,0 +1,32 @@
+pub mod pb {
+    tonic::include_proto!("/grpc.examples.echo");
+}
+
+use pb::{echo_client::EchoClient, EchoRequest};
+use tonic::transport::{Certificate, Channel, ClientTlsConfig};
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let pem = tokio::fs::read("tonic-examples/data/tls/ca.pem").await?;
+    let ca = Certificate::from_pem(pem);
+
+    let tls = ClientTlsConfig::with_rustls()
+        .ca_certificate(ca)
+        .domain_name("example.com");
+
+    let channel = Channel::from_static("http://[::1]:50051")
+        .tls_config(tls)
+        .connect()
+        .await?;
+
+    let mut client = EchoClient::new(channel);
+    let request = tonic::Request::new(EchoRequest {
+        message: "hello".into(),
+    });
+
+    let response = client.unary_echo(request).await?;
+
+    println!("RESPONSE={:?}", response);
+
+    Ok(())
+}