chore(merge) feature/event-system-cleanup (#13)

* feat(event-system) better communication interface

* feat(proton) update main.rs

* test

* Revert "test"

This reverts commit 68daf6eeb7.

lib/rust/src/api/cmd.rs

@@ -53,10 +53,9 @@ pub enum Cmd {
     handler: String,
     once: bool,
   },
-  #[cfg(any(feature = "all-api", feature = "answer"))]
-  Answer {
-    event_id: String,
+  #[cfg(any(feature = "all-api", feature = "emit"))]
+  Emit {
+    event: String,
     payload: String,
-    salt: String,
   },
 }