boot: bootutil: Refactor some functions to have state

Refactors some functions so that the state variable is present in it

Note: This PR has been modified from the upstream commit due to
a merge failure from other changes that are not being brought into
Zephyr 3.7

Signed-off-by: Jamie McCrae <jamie.mccrae@nordicsemi.no>
(cherry picked from commit 2fe9cd4b)