fix: p2p encoding, metadata

[Vid201]

This PR fixes connection problems with Skandha. We successfully establish connection and ping each other 🚀

@zsluedem There are several things we will have to do:

• we should probably move encoding logic to separate file (like in lighthouse: https://github.com/sigp/lighthouse/blob/stable/beacon_node/lighthouse_network/src/rpc/codec/ssz_snappy.rs)
• handle result chunks codes
• update encoding for other reqresp message since they are not encoded correctly (i.e., if the list is in response you need to insert response chunk before each element of list)

Still useful to merge this so we can setup some p2p network in bundler test executor tests.

[zsluedem]

Great work.