Allow setting no confirmation on each source

[chevdor]

It would be nice to be able to define a default per repo. For instance, using my local repo would imply -y by default while using a public repo would require the -y.

[gep13]

That's a very interesting idea! 👍

[TheCakeIsNaOH]

I have been playing around with this, and it looks like this will require chocolatey/nuget-chocolatey#6 to be implemented first.
If there are sources with and without the auto confirmation, then there is not a good way to figure out which source the nuget package is coming from.