Merge #7749: Enforce expected outbound services

ecd7fd3 Introduce REQUIRED_SERVICES constant (Pieter Wuille)
ee06e04 Introduce enum ServiceFlags for service flags (Pieter Wuille)
15bf863 Don't require services in -addnode (Pieter Wuille)
5e7ab16 Only store and connect to NODE_NETWORK nodes (Pieter Wuille)
fc83f18 Verify that outbound connections have expected services (Pieter Wuille)
3764dec Keep addrman's nService bits consistent with outbound observations (Pieter Wuille)