Rewrite AbstractAuthenticationTargetUrlRequestHandler#determineTargetUrl logic for clarity

[dkodippily]

Added new test class AbstractAuthenticationTargetUrlRequestHandlerTests to confirm AbstractAuthenticationTargetUrlRequestHandler. determineTargetUrl() behaviour.

[jzheaux]

Thanks, @dkodippily! I've left some feedback inline. Also, once you get to refactoring the class under test, will you please squash your commits like so:

1. one commit for the tests, followed by
2. one commit for the refactor

The first commit should end with Issue gh-12344 and the second comment should end with Closes gh-12344.

[dkodippily]

Thanks, @dkodippily! I've left some feedback inline. Also, once you get to refactoring the class under test, will you please squash your commits like so:

1. one commit for the tests, followed by
2. one commit for the refactor

The first commit should end with Issue gh-12344 and the second comment should end with Closes gh-12344.

@jzheaux Thanks for the comments , I've added the changes

[jzheaux]

Thanks, @dkodippily! I've left some feedback inline about the latest changes.

[dkodippily]

Thanks, @dkodippily! I've left some feedback inline about the latest changes.

Thanks , @jzheaux , I've pushed the changes.

[jzheaux]

Thanks, @dkodippily! This is now merged into main. I also added a polish commit to simplify the if statements down to unary conditions.

[dkodippily]

Thanks, @dkodippily! This is now merged into main. I also added a polish commit to simplify the if statements down to unary conditions.

Thank you @jzheaux for the support and guidance, planning to pick another issue soon :)