Add a test that checks that both advertisers, the legacy and the
extended behaves identically when the stack is suspended, in particular:
- `bt_mesh_send_cb.end` callback is called with error code `0` for the
advertisement that the advertiser already pushed to the ble host
(called `bt_mesh_send_cb.start`),
- `bt_mesh_send_cb.start` callback with error `-ENODEV` is called for
every advertisement that was pushed to the mesh advertiser using
`bt_mesh_adv_send` function before the stack was suspended,
- `bt_mesh_adv_create` returns NULL when attempting to create a new
advertisement while the stack is suspended.
The `bt_mesh_adv_disable` is called from the work because calling it
from the `bt_mesh_send_cb.start` callback will cause a deadlock.
Signed-off-by: Pavel Vasilyev <pavel.vasilyev@nordicsemi.no>
30ccd55f4c