[rpc] Add connection type to getpeerinfo RPC, update tests

Summary:
This is a backport of core#19725 [2/5]
https://github.com/bitcoin/bitcoin/pull/19725/commits/395acfa83a5436790c1a722a5609ac9d48df235f

Depends on D10371

Test Plan: ninja all check-all

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D10372