Draft: Refactor ticket update services

Unite services that send provisioning articles to OTRS tickets

• Create class "update_process_ticket_with_provisioning_information.py" and its test
• Remove the three classes that are covered with it, and their tests:
  • update_process_ticket_with_VF_provisioning.py
  • update_process_ticket_with_MM_success_answer.py
  • update_process_ticket_with_completed_order_item.py
• Update CHANGELOG.md

Move article classes to an "articles" folder And article tests to "tests/otrs_models/articles" folder

Inherit _body_from_dct method from AbstractArticle

Add service to warn OTRS about a completed MM OrderItem

• Update update_process_ticket_with_MM_error.py and update_process_ticket_with_MM_success_answer.py with this new feature purpose.