PR #23733 was supposed to deprecate and remove the ability to compare
Hash objects with AC::Parameters objects. Unfortunately it seems that
we still accidentally support that.

This PR adds a deprecation warning so that we can remove it in the
future.

Unfortunately the deprecation message is showing for a few tests and I'm not 100% sure how we should proceed.

We are delegating some methods to the underlying hash, but other methods have their own implementation.

One specific example is ActionController::Parameters#values vs ActionController::Parameters#each_value. These two methods can hand back different objects:

require "minitest/autorun"
require "active_support/all"
require "action_controller/metal/strong_parameters"

class ParametersMemberTest < Minitest::Test
  def test_ok
    hash = { "foo" => { "bar" => :baz } }
    params = ActionController::Parameters.new(hash)
    p params.values
    p params.each_value.to_a
  end
end

Output is:

$ bundle exec ruby -I activesupport/lib/:actionpack/lib thing.rb
Run options: --seed 23907

# Running:

[{"bar"=>:baz}]
[#<ActionController::Parameters {"bar"=>:baz} permitted: false>]
.

Finished in 0.000400s, 2499.9999 runs/s, 0.0000 assertions/s.
1 runs, 0 assertions, 0 failures, 0 errors, 0 skips

The above behavior leads to an odd case where params.values doesn't equal params.each_value.to_a and we have a test for that here.

IMO we need to stop delegating any methods to the underlying hash, or at least drastically restrict them, but I'm somewhat worried about compatibility.