Feature Link Invalid/Broken Links Check should check for more than 404

The Feature Link Invalid/Broken Links Check only seems to explicitly check for 404 errors. This feature should instead check for != 200 or allow use to enter a list of error codes.

Our issue is with S3 hosted features, which return a 403 instead of 404. Their logic is that an 404 error gives too much information and a 403 is better. This can be fixed by altering the bucket configuration but would be nice if we could add additional error codes.