Pass block directly to internal_request_eval handler

[janko]

I was looking at the inspect output of the internal request instance for a named auth class when using internal_request_eval, and I noticed it was busier than I expected:

#<RodauthMain::InternalRequest:0x0000000138feb710
 @internal_request_block=
  #<Proc:0x0000000138ff09e0 /Users/janko/.rbenv/versions/3.0.1/lib/ruby/gems/3.0.0/bundler/gems/rodauth-rails-9152ba36c4c5/lib/rodauth/rails.rb:29>,
 @internal_request_return_value=#<RodauthMain::InternalRequest:0x0000000138feb710 ...>,
 @params={},
 @scope=#<RodauthApp:0x0000000138feaec8 @_request=#<RodauthApp::RodaRequest POST />, @_response=#<RodauthApp::RodaResponse nil {} []>>,
 @session={}>

In rodauth-rails, there is a wrapper around internal_request_eval that returns the internal request instance, so it would be easy for me to remove @internal_request_block and @internal_request_return_value instance variables there before returning the instance.

However, it didn't seem to me like it was necessary to assign the block passed to internal_request_eval to an attribute accessor, so I made the change to pass the block down directly through the method chain. Let me know what you think of this change.

[jeremyevans]

The block deliberately set to an attribute, so that any time while handling an internal request, you can call the block to get per-request behavior. I guess there isn't an example of using this in the specs, but there probably should be.

[janko]

I see, that makes sense, I didn't realize that was a feature for other internal request methods 👍🏻