Bluetooth: host: Add RPA in directed advertisement support

In order to advertise directed to a privacy enabled central the
initiator field of the directed adv packet needs to set to an RPA.
To instruct the controller to use an RPA in the initiator field own
address type should be set to either 0x02 or 0x03.
Since it is not certain that a remote device supports address resolution
of the initiator address we add an option to turn this on and give the
application the responsibility to check if peer supports this.

Fixes #14743

Signed-off-by: Joakim Andersson <joakim.andersson@nordicsemi.no>