bluetooth: controller: Implemented dynamic re-scheduling in ticker

As a part of a ticker extension interface, it is now possible to specify
a slot_window when starting a ticker. When setting the
ticks_slot_window to a non-zero value, it is requested that the node
timeout is re-located to a position within the window, where the node
does not collide with other nodes - aligning to the end of the window.
The solution takes into consideration if a node has already been
updated with drift correction (e.g. ADV randomization), subtracting this
from the window.

Signed-off-by: Morten Priess <mtpr@oticon.com>