API for creating command sender which forwards feedback

paper-server/src/main/java/org/bukkit/craftbukkit/command/ServerCommandSender.java

@@ -12,7 +12,7 @@ import org.bukkit.permissions.PermissionAttachmentInfo;
 import org.bukkit.plugin.Plugin;
 
 public abstract class ServerCommandSender implements CommandSender {
-    private final PermissibleBase perm;
+    public final PermissibleBase perm; // Paper
     private net.kyori.adventure.pointer.Pointers adventure$pointers; // Paper - implement pointers
 
     protected ServerCommandSender() {

paper-server/src/main/java/org/bukkit/craftbukkit/command/VanillaCommandWrapper.java

@@ -86,6 +86,11 @@ public final class VanillaCommandWrapper extends BukkitCommand {
         if (sender instanceof ProxiedCommandSender) {
             return ((ProxiedNativeCommandSender) sender).getHandle();
         }
+        // Paper start
+        if (sender instanceof io.papermc.paper.commands.FeedbackForwardingSender feedback) {
+            return feedback.asVanilla();
+        }
+        // Paper end
 
         throw new IllegalArgumentException("Cannot make " + sender + " a vanilla command listener");
     }