Fix: qualify bare Faker constant references to support lazy loading

[javier-menendez]

Motivation / Background

Prefix unresolved calls to Number, Date, Lorem, and Time with Faker:: in Code, Crypto, Omniauth, and Types so they resolve correctly when FAKER_LAZY_LOAD=1 defers autoloading

Generators failing with lazy enabled

Faker::Code.nric
Faker::Code.rut
Faker::Crypto.md5
Faker::Crypto.sha1
Faker::Crypto.sha256
Faker::Omniauth.apple
Faker::Omniauth.auth0
Faker::Omniauth.facebook
Faker::Omniauth.github
Faker::Omniauth.google
Faker::Omniauth.linkedin

Example to reproduce

FAKER_LAZY_LOAD=1 bundle exec irb
irb(main):001> require 'faker'
=> true
irb(main):002> Faker::Code.nric
/home/user/faker/lib/faker/default/code.rb:95:in 'Faker::Code.nric': undefined method 'birthday' for class Date (NoMethodError)