e4e3b44e9cc7227b3ad765397c884999f57bac2e net: call `Select` with reachable networks in `ThreadOpenConnections` (brunoerg)
829becd990b504a2e8a57fa8a6ff6ac6ae8ff900 addrman: change `Select` to support multiple networks (brunoerg)
f698636ec86c004ab331994559c163b7319e6423 net: add `All()` in `ReachableNets` (brunoerg)
Pull request description:
This PR changes addrman's `Select` to support multiple networks and change `ThreadOpenConnections` to call it with reachable networks. It can avoid unnecessary `Select` calls and avoid exceeding the max number of tries (100), especially when turning a clearnet + Tor/I2P/CJDNS node to Tor/I2P/CJDNS. Compared to #29330, this approach is "less aggresive". It does not add a new init flag and does not impact address relay.
I did an experiment of calling `Select` without passing a network until it finds an address from a network that compose 20% ~ 25% of the addrman (limited to 100 tries).

ACKs for top commit:
achow101:
ACK e4e3b44e9cc7227b3ad765397c884999f57bac2e
vasild:
ACK e4e3b44e9cc7227b3ad765397c884999f57bac2e
naumenkogs:
ACK e4e3b44e9cc7227b3ad765397c884999f57bac2e
Tree-SHA512: e8466b72b85bbc2ad8bfb14471eb27d2c50d4e84218f5ede2c15a6fa3653af61b488cde492dbd398f7502bd847e95bfee1abb7e01092daba2236d3ce3d6d2268