Add a to_any helper in the containerd client crate

This provides a solution to Any->type matching that happens on
the containerd Go-based server side where the Any types in prost
use typeurl as defined in the protobuf spec and the server side
is matching on the fullname property of the type.

Signed-off-by: Phil Estes <estesp@amazon.com>

crates/client/src/lib.rs

@@ -119,6 +119,19 @@ pub async fn connect(
     Ok(channel)
 }
 
+use prost::{Message, Name};
+use prost_types::Any;
+
+// to_any provides a helper to match the current use of the protobuf "fullname" trait
+// in the Go code on the gRPC server side in containerd when handling matching of Any
+// types to registered types on the server. Further discussion on future direction
+// of typeurl in this issue: https://github.com/containerd/rust-extensions/issues/362
+pub fn to_any<T: Message + Name>(m: &T) -> Any {
+    let mut anyt = Any::from_msg(m).unwrap();
+    anyt.type_url = T::full_name();
+    anyt
+}
+
 /// Help to inject namespace into request.
 ///
 /// To use this macro, the `tonic::Request` is needed.