introduce a proper address pipeline

[marten-seemann]

We need to get a lot smarter about address management. Wrapping / replacing addresses via the AddrsFactory doesn't scale.

I'm imagining a new service that's responsible for the entire process of address management.

1. It ingests in new "address candidates" from various sources: user provided address hints, transports claiming to listen on certain addresses, Identify, relay service etc.
2. It verifies these addresses using AutoNAT v2.
3. It groups and categorizes these addresses (public / private / relayed).
4. It provides interfaces to make these different categories of addresses available to consumers.

Updated(@sukunrt): Using this issue for tracking:

• Implement AutoNATv2 #2422

Tasks

• autorelay: send addresses on eventbus; dont wrap address factory #3071
• addrsmanager: extract out addressing logic from basichost #3075
• basichost: use autonatv2 to verify reachability #3231

[sukunrt]

We need something like #2293 to test this.