Handle forbidden auth check with token user ID

[davidrimshnick]

Describe what the PR does:

SimpliSafe can return 403 Forbidden from api/authCheck even after successfully issuing a valid access token. When that specific response occurs, decode the http://simplisafe.com/uid claim from the newly issued access token and use it as the account user ID.

All other HTTP failures continue to propagate unchanged, and a 403 still propagates when the token is malformed or does not contain a usable user ID.

Does this fix a specific issue?

Related to home-assistant/core#149151

Checklist:

• Confirm that one or more new tests are written for the new functionality.
• Run tests and ensure everything passes (with 100% test coverage).
• README update is not needed because this changes no public API.

Testing:

• pytest --cov simplipy tests: 97 passed, 100% coverage
• Ruff formatting and lint: passed
• isort: passed
• mypy: passed