[libbladeRF] Name worker threads

[jynik]

It has been requested that the sync worker threads be named in order to help out when debugging. Using this issue to track status on this.

[jynik]

This appears to be possible through non-standard calls, so it may be a bit of a pain to address this in a cross-platform manner.

https://stackoverflow.com/questions/2369738/can-i-set-the-name-of-a-thread-in-pthreads-linux/7989973#7989973

[jynik]

As addressing this in a cross-platform manner would become rather messy and the benefit is rather minimal, I'm marking this "wontfix" and closing this issue.

If you're debugging and want named threads, it's simple enough to add the one or two calls where you want them, as it pertains to your specific OS/distro.