Merge bitcoin/bitcoin#29436: net: call Select with reachable networks in ThreadOpenConnections

e4e3b44e9c net: call `Select` with reachable networks in `ThreadOpenConnections` (brunoerg)
829becd990 addrman: change `Select` to support multiple networks (brunoerg)
f698636ec8 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).

  ![Screenshot 2024-02-14 at 14 37 58](https://github.com/bitcoin/bitcoin/assets/19480819/7b6863a5-d7a6-40b6-87d5-01667c2de66a)

ACKs for top commit:
  achow101:
    ACK e4e3b44e9c
  vasild:
    ACK e4e3b44e9c
  naumenkogs:
    ACK e4e3b44e9c

Tree-SHA512: e8466b72b85bbc2ad8bfb14471eb27d2c50d4e84218f5ede2c15a6fa3653af61b488cde492dbd398f7502bd847e95bfee1abb7e01092daba2236d3ce3d6d2268

src/bench/addrman.cpp

@@ -133,7 +133,7 @@ static void AddrManSelectByNetwork(benchmark::Bench& bench)
     FillAddrMan(addrman);
 
     bench.run([&] {
-        (void)addrman.Select(/*new_only=*/false, NET_I2P);
+        (void)addrman.Select(/*new_only=*/false, {NET_I2P});
     });
 }