uwb: Add vts tests for UWB HAL

No target to run the tests yet. So, just starting the VTS test suite for
UWB with some simple tests.

Also, modified the reference HAL implementation to emulate the startuo
flow.

Bug: 191175259
Test: atest VtsHalUwbTargetTest (using reference HAL on cuttlefish)
Change-Id: I2f01a3fec3324e85123d1d17e1b03dd284aee7b1