tests: Bluetooth: Add advanced BIG create BSIM test

Extended the ISO broadcaster BSIM test with an additional
step to create a BIG using the test parameters.

Since this isn't properly implemented in the controller,
CONFIG_BT_ISO_ADVANCED has not been enabled in the
prj.conf yet.

Signed-off-by: Emil Gydesen <emil.gydesen@nordicsemi.no>