refs #8432 - change foreman.url to proxy.url, support sending to proxy

1) rename foreman.url to proxy.url
2) add a parameter ```proxy.type``` (which should be set to ```proxy``` for smart proxy)
3) if ```proxy.type == 'proxy'``` then alter the url to smart proxy url.
I see, my pseudocode is incorrect, take it for inspiration. My goal was to issue some error/warning when things are not set appropriately. To be honest, I don't think we need to check if proxy.type is set to either foreman or proxy but it wont definitely hurt. Please refactor the method, it can look definitely better.