feat(l1): add p2p context (#1794)

**Motivation**

There are many shared attributes in all p2p tasks:

- Local node
- Signer
- TCP and UDP addresses
- RLPX message Broadcaster. 
- Kademlia table.

This makes the number of arguments big in all calls, and sometimes even
repeated (e.g. addresses + node). Additionally, Adding a new argument
related to all, like the broadcaster, also requires adding it
everywhere.

**Changes**

This PR adds a `Context` struct with all the mentioned common fields and
uses it instead of the individual fields. There's also 2 new helpers in
the `Node` struct, for udp and tcp addresses.

Author: Arkenan