Bluetooth: common: Add build asserts for address struct sizes

In some HCI packed structures we place non-packed structs inside (in
particular the address structs).
Alignment is not an issue for those because all their members are just
byte-aligned, but size is. If the compiler ever packs those it would
become a real problem, and so detect this at build time.
See the link below for more info:
https://stackoverflow.com/a/66389167



Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>