Move BlockingQueue.h to libinput

This is already useful in several places, and it's going to be also
useful in the future when InputConsumer is refactored.

So let's move it to include/input.

Bug: 311142655
Test: m inputflinger_blocking_queue_fuzzer
Change-Id: Idfc492c6bfc3cccab7e0b0d12b21a41a954cc44b