[partial regression] Do not require a runtime in order to use net sockets

[dignifiedquire]

Some details and background libp2p/rust-libp2p#1612 (comment)

[dignifiedquire]

As far as I can tell, the issue is that resolving socketaddrs can block at the moment, meaning we need some kind of blocking executor.

To fully resolve this getaddrinfo needs to be async.

• on unix systems I believe we can do this using https://man7.org/linux/man-pages/man3/getaddrinfo_a.3.html
• for osx there seems to be some ideas here:
  • https://lists.gnu.org/archive/html/emacs-devel/2016-05/msg00526.html
  • https://eggerapps.at/blog/2014/hostname-lookups.html
• on windows we can use GetAddrInfoEx for newer (Vista and later) https://stackoverflow.com/questions/6998309/is-there-a-non-blocking-method-for-host-resolution-in-winapi

https://github.com/c-ares/c-ares has likely some good details under the hood as well

[dignifiedquire]

there seems to be sth at least in android: https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.7-4.6/+/refs/heads/jb-dev/sysroot/usr/include/netdb.h#661

[dignifiedquire]

After talking to @stjepang the dns resolution is not the actual issue, we need to ensure the reactor is actually running.