Added support for IMS Bearer tokens without require any session and security tokens

[mkiki]

Description

Campaign V8.5 supports direct authentication with IMS Bearer tokens, which means there's no need any more to call the Logon or BearerTokenLogon: a IMS Bearer token passed in the Authorization header is enough to authenticate.

How Has This Been Tested?

Unit tests

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] I have signed the Adobe Open Source CLA.
• [x] My code follows the code style of this project.
• [x] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING document.
• [x] I have added tests to cover my changes.
• [x] All new and existing tests passed.