Add inspect to ActiveStorage::Service, ActiveStorage::Service::Registry, and ActiveStorage::Service::Configurator

This was inspired by #50405.

If you accidentally pretty print `ActiveStorage::Blob.services` and
have the entire config which may contain secrets persit in logs or
elsewhere.

Or in Ruby 3.2 and older, raising an exception on those objects, e.g.
`ActiveStorage::Blob.services[:local]` instead of `fetch`.

Before:

```ruby
pp ActiveStorage::Blob.services
  #<ActiveStorage::Service::Registry:0x00007f2a68469d28
    @configurations={
      :s3 => {
        :service=>"S3",
        :access_key_id=>"test_key",
        :secret_access_key=>"test_secret",
        :region=>"us-east-1",
        :bucket=>"rails-test"
      },
      :gcs => { :service=>"GCS", :credentials=> "secret-hash" }
    }
    @services={}>
```

After

```ruby
  #<ActiveStorage::Service::Registry configurations=[:s3, :gcs]>
```