Remove bad encoding middleware (#12931)

Revert #12741

app/middleware/handle_bad_encoding_middleware.rb

@@ -1,18 +0,0 @@
-# frozen_string_literal: true
-# See: https://jamescrisp.org/2018/05/28/fixing-invalid-query-parameters-invalid-encoding-in-a-rails-app/
-
-class HandleBadEncodingMiddleware
-  def initialize(app)
-    @app = app
-  end
-
-  def call(env)
-    begin
-      Rack::Utils.parse_nested_query(env['QUERY_STRING'].to_s)
-    rescue Rack::Utils::InvalidParameterError
-      env['QUERY_STRING'] = ''
-    end
-
-    @app.call(env)
-  end
-end