Merge #15144: [refactor] CNode: Use C++11 default member initializers
fac2f5ecae96dd11057977ce988501e18bb162c6 Use C++11 default member initializers (MarcoFalke)
Pull request description:
The second and last change on this topic (c.f. #15109). Split up because the diff would otherwise interleave, making review harder than necessary.
This is not a stylistic change, but a change that avoids bugs such as:
* fix uninitialized read when stringifying an addrLocal #14728
* qt: Initialize members in WalletModel #12426
* net: correctly initialize nMinPingUsecTime #6636