use `Rack::Utils.unescape_path` to unescape paths

Escaping and unescaping paths is different than query parameters, and we
need to respect that.  This commit uses the new method in Rack to escape
and unescape paths.  Fixes #11816

Gemfile.lock

@@ -29,7 +29,7 @@ GIT
 
 GIT
   remote: git://github.com/rack/rack.git
-  revision: 6c4160b8c5173299f4b49ea2c9e4aab76f6b9054
+  revision: 4080d56bb30f26a2f09053de702896104b5fb64d
   branch: master
   specs:
     rack (2.0.0.alpha)

actionpack/lib/action_dispatch/middleware/static.rb

@@ -28,7 +28,7 @@ module ActionDispatch
     # Used by the `Static` class to check the existence of a valid file
     # in the server's `public/` directory (see Static#call).
     def match?(path)
-      path = URI.parser.unescape(path)
+      path = ::Rack::Utils.unescape_path path
       return false unless path.valid_encoding?
       path = Rack::Utils.clean_path_info path
 
@@ -43,7 +43,7 @@ module ActionDispatch
         end
 
       }
-        return ::Rack::Utils.escape(match)
+        return ::Rack::Utils.escape_path(match)
       end
     end
 
@@ -90,7 +90,7 @@ module ActionDispatch
       def gzip_file_path(path)
         can_gzip_mime = content_type(path) =~ /\A(?:text\/|application\/javascript)/
         gzip_path     = "#{path}.gz"
-        if can_gzip_mime && File.exist?(File.join(@root, ::Rack::Utils.unescape(gzip_path)))
+        if can_gzip_mime && File.exist?(File.join(@root, ::Rack::Utils.unescape_path(gzip_path)))
           gzip_path
         else
           false