tests: Bluetooth: bsim_advx_test: Add some tests for scan response
tests: Bluetooth: bsim_advx_test: Add some tests for scan response

This adds few tests for handling scan response in ext commands:
- trying to set scan response on non-scannable instance should fail
- it should be possible to create scannable instance, set scan data,
  enable and then disable set

Signed-off-by: Andrzej Kaczmarek <e629a10adbe722145f074acb1ca27e72d94cfcb5@codecoup.pl>

zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,nashif/zephyr,galak/zephyr,finikorg/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,Vudentz/zephyr,galak/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,nashif/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,Vudentz/zephyr,Vudentz/zephyr,nashif/zephyr,nashif/zephyr