[NEW FEATURE] add peer reliability statistics

[Bitcoinite]

Motivation: Since June 2022, the Tor Network is under intense DDoS Attacks, which causes significant issues with the connection stability and reliability of peers that are on a Tor only connection. In addition to that, there are some peers out there in the Lightning Network, that are hosted on a hybrid Tor/IPv4 Setup, but are suffering under a bad overall internet connection. As we know, this can lead to costly force closes, that could be prevented by closing unreliable channels before they FC due to a pending HTLC. As of now, LNDg has no possibility built in, to analyse the connection stability/reliability of your peers.

Suggested Feature: Add logging for peer connection stability/reliability:

• Number of disconnects
• Time until the peer comes back online
• Total time online/offline
• Total time of channel disabled states

From these stats, a classification of your peers, in regard of connection quality, should be possible. This would give at least an overview about how stable each peer is.