api: call multiple methods atomically (useful in async contexts)

remove unused response_id parameter of handle_nvim_... helpers

src/nvim/api/private/defs.h

@@ -33,8 +33,8 @@ typedef enum {
 /// Used as the message ID of notifications.
 #define NO_RESPONSE UINT64_MAX
 
-/// Used as channel_id when the call is local
-#define INVALID_CHANNEL UINT64_MAX
+/// Used as channel_id when the call is local.
+#define INTERNAL_CALL UINT64_MAX
 
 typedef struct {
   ErrorType type;

src/nvim/api/private/dispatch.h

@@ -4,7 +4,6 @@
 #include "nvim/api/private/defs.h"
 
 typedef Object (*ApiDispatchWrapper)(uint64_t channel_id,
-                                     uint64_t request_id,
                                      Array args,
                                      Error *error);