url payload generator should detect all-caps protocol

[mharen]

Summary

Updates Url Payload Generator to better handle when a given url includes HTTP/HTTPS.

This PR fixes/implements the following bugs/features:

• Bug: URL Payload Generator incorrectly prefixes http:// to inputs that already include HTTP://

Test plan

• unit test added to verify correct behavior
• make sure solution builds and tests run sucessfully

[Shane32]

The changes here do not fail any tests. I suggest merging the PR.

[mharen]

Thanks!

[codebude]

Hi @mharen , hi @Shane32 ,

thanks for your help. The change fixes the problem, thus I merged it. :-)
In future I propably will replace it by a Regex, because I think the startswith solution is somehow weak. Think about an input like "http-service.com". It would be matched by the startswith and the generator wouldn't prefix it, even if the protocol is missing.
With an Regex we may avoid it: https://regex101.com/r/PbTCnq/1