- This prevents a malicious user from crafting a redirect
  URL to a nefarious site under their control.

Introduce a utility function `uriFromURL` to strip host information from
redirect URLs, ensuring redirects remain local. This mitigates potential
security risks by preventing redirects to external malicious sites.

Changes:
- Modify OAuth2 and OIDC callback logic to utilize `uriFromURL`.
- Enhance related test cases for preventing external redirects.

This work ensures secure handling of redirect URLs across the application.

- Removed an unnecessary blank line for code consistency.

- Improve handling of redirect logic in FakeIDP.
- Ensure existing CheckRedirect functions are respected.
- Enhance OIDC login test to handle redirects properly.

- Improve handling of redirect logic in FakeIDP by ensuring existing CheckRedirect functions are respected.
- Enhance related test cases for better testing of redirect behaviors.

Changes:
- Store claims if state is available before falling back to existing CheckRedirect.
- Ensure HTTP client transport is set to default in tests before assigning CheckRedirect.

Removing a leftover debug print statement to clean up the code.

- Prevent redirecting the last step in the OIDC flow involving the state
  parameter, ensuring it remains part of the core OIDC process.
- This ensures secure and consistent handling of redirects in the OIDC
  login flow.

Update the OAuth redirect URL test to exclude fragment

Previously, the test included a fragment in the constructed URL.
Removing the fragment ensures consistency with the actual URL format
used in the application.