backport: p2p timeout from 2.1

[matthewdarwin]

**EOSUSA Michael, [14.03.22 10:48]
i think there were 2 parts... one is the p2p issue where it would get all peers unlinkable.... did the fixes also include anything related to the original issue where the p2p sessions hang open for 15min (which is what triggers all those unlinkable blocks in the first place)

Kevin Heifner, [14.03.22 10:49]
The timeout feature is in 2.1, it will need to be back-ported to Mandel**

[matthewdarwin]

Kevin Heifner, [14.03.22 13:39]
Not the p2p-keepalive-interval-ms in 2.1

[heifner]

Included as part of #169