AUTH-6145 support multi-valued + service token auth for scim provisioning

[khiller-cf]

Description

Support Access Service Tokens as an authentication method for SCIM provisioning to Access Applications. Additionally, support configuring multiple authentication methods for SCIM provisioning to Access applications. This is useful when you have an application behind Access, but the SCIM provider also has its own authentication method.

Has your change been tested?

Unit tests

Screenshots (if appropriate):

Types of changes

What sort of change does your code introduce/modify?

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

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.
• This change is using publicly documented in cloudflare/api-schemas
  and relies on stable APIs.

[github-actions]

changelog detected ✅

[jacobbednarz]

as this is exporting a global constant, we'll want to namespace it.

Suggested change

	ScimAuthenticationAccessServiceToken AccessApplicationScimAuthenticationScheme = "access_service_token"
	AccessApplicationScimAuthenticationAccessServiceToken AccessApplicationScimAuthenticationScheme = "access_service_token"

[jacobbednarz]

you'll want to update the rest of the usage of this as well to make sure it all still works.