Support method sending in generate_payload if they match schema field names

[DeeChau]

When an ActiveRecord class has a method with the same name as a field in the schema, the generate_payload method should be able to populate the payload with that field.

An example of this is when initial is a field in the kafka schema, there should be no additional code to add to generate_payload

class Widget < ApplicationRecord
  # Quite literally the first letter of the name
  def initial
    name.first
  end
end
# == Schema Information
#
# Table name: widgets
#
#  name   :string(6)        not null, primary key