Add broadcast support to the CAP initiator sample.
This adds new sample-specific Kconfig options to help
select the right Kconfig options based on whether
unicast, broadcast or both is being used.
This also moves common TX functionality
to cap_initiator_tx to reuse the same TX thread
and functionality.
Finally there is a babblesim implemented for
the broadcast. There is not broadcast support for the
CAP acceptor sample yet, so this test only verifies that we
get the TX complete events from the controller.
Signed-off-by: Emil Gydesen <emil.gydesen@nordicsemi.no>
