Rename some status codes (#17)

IceRpc/Internal/IceRpcDefinitions.slice

@@ -35,7 +35,7 @@ compact struct IceRpcRequestHeader {
 [cs::readonly]
 compact struct IceRpcResponseHeader {
     statusCode: StatusCode
-    // errorMessage: string // only present when StatusCode > Success
+    // errorMessage: string // only present when StatusCode > Ok
     // fields: dictionary<ResponseFieldKey, sequence<uint8>> (encoded/decoded manually)
 }
 

IceRpc/StatusCode.slice

@@ -6,34 +6,34 @@ module IceRpc
 /// occurred. It's carried by responses.
 unchecked enum StatusCode : varuint62 {
     /// The dispatch completed successfully.
-    Success = 0
+    Ok = 0
 
     /// The dispatch failed with an application-specific error.
     ApplicationError
 
-    /// The dispatch could not find the target service.
-    ServiceNotFound
+    /// The dispatch could not find the target service or some other resource.
+    NotFound
 
-    /// The dispatch found the target service but this target service does not have the requested operation.
-    OperationNotFound
+    /// The target service was found but it does not implement the requested operation.
+    NotImplemented
 
-    /// The target service is currently unavailable and the caller can safely retry.
+    /// The server or the target service is currently unavailable and the caller can safely retry.
     Unavailable
 
-    /// The dispatch failed with an unhandled exception.
-    UnhandledException
+    /// The dispatch failed due to an internal service or server error. This is typically caused by a bug in the server
+    /// or in the target service.
+    InternalError
 
     /// The dispatch failed because the request payload could not be decoded or because a middleware could not decode
-    /// a request field. It is typically due to a mismatch of the Slice definitions (or more generally IDL definitions)
-    /// used by the invoker and the dispatcher.
+    /// a request field. It is typically due to a mismatch in the IDL definitions used by the client and the server.
     InvalidData
 
     /// The dispatch failed because it received a truncated payload. This is usually caused by a failure of the invoker
     /// while it was sending the payload.
     TruncatedPayload
 
     /// The dispatch detected the expiration of the request's deadline.
-    DeadlineExpired
+    DeadlineExceeded
 
     /// The caller is not authorized to access the requested resource.
     Unauthorized