Refactor FactoryBot module

[vburzynski]

This is an experiment with refactoring some of the sprawl of the root/core FactoryBot module.

• previously it was necessary for developers to discover that the files for aliases, find definitions, reload, and the default syntax extended the FactoryBot module
• with the refactoring the code in lib/factory_bot.rb explicitly reveals which modules extend the FactoryBot module

[neilvcarvalho]

I like it. It should break a few monkey patches given how things are moving around, but that's a risk of monkey patching. This should be included in at least a minor version release, or perhaps a major version bump depending on how far this refactor goes.