* refactor(netx/dialer): hide implementation complexity
This follows the blueprint of `module.Config` and `nodule.New`
described at https://github.com/ooni/probe/issues/1591.
* fix: ndt7 bug where we were not using the right resolver
* fix(legacy/netx): clarify irrelevant implementation change
* fix: improve comments
* fix(hhfm): do not use dialer.New b/c it breaks it
Unclear to me why this is happening. Still, improve upon the
previous situation by adding a timeout.
It does not seem a priority to look into this issue now.
We already configure a timeout in the underlying dialer, hence
there's no point in keeping the TimeoutDialer around.
Part of https://github.com/ooni/probe/issues/1507
We're currently use jafar for QA and jafar is a better mechanism,
even though it is not portable outside of Linux.
This self censorship mechanism was less cool and added a bunch
of (also cognitive) complexity to netx.
If we ever want to go down a self censorship like road, we probably
want to do as little work as possible in the problem and as much
work as possible inside a helper like jafar.
Part of https://github.com/ooni/probe/issues/1591.
