binman: Move state information into a new module

binman: Move state information into a new module

At present the control module has state information in it, since it is the
primary user of this. But it is a bit odd to have entries and other
modules importing control to obtain this information.

It seems better to have a dedicated state module, which control can use as
well. Create a new module using code from control and update other modules
to use it.

Signed-off-by: Simon Glass <sjg@chromium.org>