Adds a new field which is set to the estimated size of the
upgrade slot data, this is used to know how much space should
be reserved in an update image to determine if an update will
fit or not
Signed-off-by: Jamie McCrae <jamie.mccrae@nordicsemi.no>
Adds MCUboot's estimated overhead footer size to the application's
cache when using sysbuild, this allows that information to be
propagated to applications which can use the information to reduce
the available size for an application, preventing the MCUboot
error of image too large to swap.
Signed-off-by: Jamie McCrae <jamie.mccrae@nordicsemi.no>