USB: implement HID class-specific control requests

[hryx]

These are currently ACKed without properly performing the requested tasks:

• [ ] SetIdle: Requests bandwidth limits on the device.
• [ ] SetProtocol: Switches between boot/non-boot report formats.
• [ ] SetReport: Send report to a device, e.g. turn on a LED. Requires some architecture in MicroZig for having application code handle this event.

Follow-up from #449