FIX: Don't error out on nested topic show id param (#29274)

We're expecting the ID param to be something that neatly coerces into an ID. If we receive something like a nested parameter, this will blow up. (We already handle the case of arrays.)

This commit raises an InvalidParameters exception in the case of a nested ID.

app/controllers/topics_controller.rb

@@ -51,7 +51,7 @@ class TopicsController < ApplicationController
   end
 
   def show
-    if params[:id].is_a?(Array)
+    if params[:id].is_a?(Array) || params[:id].is_a?(ActionController::Parameters)
       raise Discourse::InvalidParameters.new("Show only accepts a single ID")
     end