[POC] Preemptive auth test

As it turns out, HC4 RRS does not authenticate preemptively.

This pull contains a UT that confirms that.

Also, there is a change in RRS that fixes the problem but _only for hosts doing Basic authentication scheme_. Unsure how would this behave if remote does Digest or NTLM auth scheme (unknown before 1st request done to it). More about this in RRS line comments.

Best we could do here is similar to the "S3 trick" (flagging is remote S3 bucket or not, known and remembered after 1st remote access), and fix this for Basic protected remote peers, but do nothing for others... if we want to handle this at all.