should handle namespaced in field/associative

[namiwang]

Say we've got some models like

module OneModule
  class OneModel < ApplicationRecord
    belongs_to :another_model, class_name: 'AnotherModel', foreign_id: 'another_model_id'
  end
end

While Rails is ok about it, administrate needs class_name to be OneModule::AnotherModel instead of just AnotherModel to work properly.

Guess the related methods is associated_class_name in field/associative.

[nickcharlton]

Do you think you'd be able to contribute a PR for this?

[pablobm]

I think this should be irrelevant now that we have automatic associations (#1633). If someone is having still this issue, please let us know and we can reopen.