refactor(swarm): express dial logic linearly

[thomaseizinger]

Description

Previously, the logic within Swarm::dial involved fairly convoluted match expressions. This patch refactors this function to use new utility functions introduced on DialOpts to handle one concern at a time.

This has the advantage that we are covering slightly more cases now. Because we are parsing the PeerId only once at the top, checks like banning will now also act on dials that specify the PeerId as part of the /p2p protocol.

Notes

I am touching this function as part of #3099 and found it hard to integrate the new callbacks into it.

Links to any relevant issues

Open Questions

Change checklist

• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• A changelog entry has been made in the appropriate crates

[thomaseizinger]

With this refactoring, we are not executing certain checks more thoroughly. For example, we make all addresses to be dialed unique and filter out the ones we listen on. Previously, those was only true for the addresses coming from WithPeerIdWithAddresses. Was that on purpose @mxinden? (I think you introduced this builder).

I think the current version is more correct so I pushed a hack that fixes the test. Alternatively, we could also change the test (and perhaps remove the other code that checks for self dials?).

[mxinden]

For example, we make all addresses to be dialed unique and filter out the ones we listen on. Previously, those was only true for the addresses coming from WithPeerIdWithAddresses. Was that on purpose @mxinden? (I think you introduced this builder).

No longer dialing duplicate addresses would fix #3209.

Not doing it everywhere but in WithPeerIdWithAddresses only was not a deliberate choice. I am in favor of doing it everywhere. Thanks.

[mxinden]

All in all a nice clean-up. Thanks @thomaseizinger. Happy my ugly deeply nested method is gone.

[thomaseizinger]

For example, we make all addresses to be dialed unique and filter out the ones we listen on. Previously, those was only true for the addresses coming from WithPeerIdWithAddresses. Was that on purpose @mxinden? (I think you introduced this builder).

No longer dialing duplicate addresses would fix #3209.

I don't think this patch fixed #3209 because we are doing the deduplication before we ensure the address has a /p2p ending.

Let's re-open #3209 for now and confirm with a test that it is actually fixed.