CLI: Ask users to allow networking capabilities if not set

[xdoardo]

(Closes #4953, fixes RUN-371)

As per title. This patch introduces a mechanism that allows users to recover from not permitted networking accesses with a prompt:

In addition, as implied by the prompt, this patch adds a mechanism to cache the users' choice in response to the prompt above.

[syrusakbary]

I believe it will be better for the user to input a single char (y/n/a, as yes/no/always) ). Rather than up/down selectable.

It's way more common for this kind of input

[syrusakbary]

This is great, I just tried locally. Can we have the following? Have the letter a prefilled in the input (that way is one less keystroke for the user)

[xdoardo]

42027b0 adds it.

[syrusakbary]

I tried this and it doesn't work. You can't delete the "a" and can't just press enter either (need to add another "a")