fix: Added more tests in error_redirect_test.go

[xlanor]

Proposed changes

With the inclusion of the new url_param config option to the redirect error handler, I have written a few additional test cases that tests it against all 3 types of redirect - HTTP redirect, HTTPS redirect, Relative URL redirect.

The diff is a little messy because I moved the original test case written by the contributor who added the feature and ordered it according to the type of redirect that was being tested.

Checklist

• I have read the contributing guidelines.
• I have read the security policy.
• I confirm that this pull request does not address a security
  vulnerability. If this pull request addresses a security. vulnerability, I
  confirm that I got green light (please contact
  [email protected]) from the maintainers to push
  the changes.
• I have added tests that prove my fix is effective or that my feature
  works.
• I have added or changed the documentation.

[aeneasr]

Awesome 🎉

Thank you for your contribution!