[SDK-3887] Always honor auth0Logout config

[adamjmcgrath]

Description

The OIDC RP Initiated Logout endpoint is incompatible with Auth0's proprietary logout. Make sure this SDK does not use it if auth0Logout is configured and an end_session_endpoint is Discovered in the OIDC Discovery document.

Testing

If auth0Logout is true -> use v2/logout regardless of discovery
If auth0Logout is false -> use discovered endpoint or nothing
If auth0Logout is not set -> use v2/logout if issuer is auth0.com else discovered endpoint if available

Checklist

• I have added documentation for new/changed functionality in this PR or in auth0.com/docs
• All active GitHub checks for tests, formatting, and security are passing
• The correct base branch is being used, if not the default branch