MC-30392: De-couple Authorize.net payment methods integrations from core in 2.4.0

[SeruyV]

Description

Overview:

We need to de-couple all the deprecated 3rd party payment methods integrations from core in 2.4.0 in order shift maintenance compliance from Magento to the vendors.

Acceptance criteria:

• Remove Authorize.Net Accept.js and Direct Post modules marked as deprecated and other code depended on these modules have to be completely removed from the code base.
• All the tests related to deprecated Authorize.net payment method have to be removed.

Fixed Issues (if relevant)

1. magento/magento2-functional-testing-framework#<issue_number>: Issue title
2. ...

Contribution checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/verification tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)
• Changes to Framework doesn't have backward incompatible changes for tests or have related Pull Request with fixes to tests