Are we sure we want to hardcode nonblocking mode for sockets?

[egnima]

Although non-blocking network operations are often preferred in gamedev, there are also plenty of times it's easier (and more CPU efficient) to use the operating systems designated blocking receive mode instead of while looping on a receive, especially if it's in a designated child thread.

I've started working on a PR that would add SetSocketBlockingMode and GetSocketBlockingMode (with nonblocking mode still the default), but I wasn't sure if that's the direction this library is going in. What do you experienced SDLers think?