- macOS behaviour of setRealtime now matches other platforms

MR feedback

- added unit tests
- best performance timers used for each platform
- fixed an issue in which timer callbacks could drift

This commit adds fixes for generating unique hardware IDs on Windows. The SMBIOS is parsed to generate a unique ID based on hardware factors of the local machine.

The issue affected projects not depending on juce_audio_devices.

Previously, JUCE_ANDROID_REALTIME_THREAD_AVAILABLE sometimes remained
unset, even though JUCE_USE_ANDROID_OBOE was set to its default value.
This is because in this case, JUCE_USE_ANDROID_OBOE is only defined in
juce_audio_basics.h, so it is not visible when compiling juce_core.cpp.

This is a breaking change - see BREAKING-CHANGES.txt