tests: usb: uac2: test High-Speed descriptor macros

Generate and test both Full-Speed and High-Speed descriptors against
reference values. Verify that IAD, interface and endpoint descriptors
are not shared between Full-Speed and High-Speed descriptor sets because
the number of non-UAC2 interfaces can be different at different speeds
and thus the assigned interface numbers and endpoint numbers can differ.

Signed-off-by: Tomasz Moń <tomasz.mon@nordicsemi.no>