Implement user feedback when guessing pkgs

[JesperBrink]

We use a heuristic right now for finding the correct packages. This is not always correct and it would therefore be nice to be able to ask the user, if we are choosing the correct package, if there are multiple to choose from.

Eg.

We have found a dependency relation and multiple packages which potentially fulfils
this relation, but are in doubt of which one to choose:
    1. python-bioformats
    2. bioformats
    3. bioformats2

[JesperBrink]

Give the user the option to just go for our first choice, or choose a specific from the list (based on index).
Make sure that y <enter> picks the first one for testing purpose with yes

[Hogfeldt]

@JesperBrink isn't this implemented at the moment?