Do not require credentials to be entered for Anonymous web data sources

[fbcideas_migusr]

For data sources which are anonymous web endpoints, it seems a bit silly that I have to go click through "enter credentials" every time I upload my PBIX. They are anonymous - it should work on its own, or at least try rather than failing to refresh the datasource due to missing credentials.

[angryanalytics]

My votes for this item is because we also have to use Anonymous when trying to broker an OAuth flow. Because the OAuth flow is not supported natively, we have to use M Script to pass creds to an authorization service using "Web.Contents" and then pass that token retrieved to the next "Web.Contents" call to get the result. The PowerBI service should act as the power bi desktop and allow the flow to occur instead of statically checking for a valid 200 response. It would also work to allow an "override" option to say "yes, I know this is returning a 403/404 but trust me, I know what I am doing".