Fixed getting min/max drop values from deconstruction when modifier is NULL

[achpile]

Summary

Bugfixes "Wrong information on furniture deconstruction"

Purpose of change

Fixes #75308

Function Single_item_creator::every_item_min_max() used modifier->count to get min/max amount of items you get from deconstruction.
Since modifier is std::optional it is not always provided

Describe the solution

Check if modifier is not NULL. If it is - we return [1,1] if item drop chance is 100 and [0,1] if it is less.

Describe alternatives you've considered

None

Testing

Tried to deconstruct heavy machinery and got perfect results

Additional context

[zachary-kaelan]

If there's any deconstruct test in the unit tests, this might be a good thing to add. If it can get broken once it can get broken again.

[achpile]

If there's any deconstruct test in the unit tests, this might be a good thing to add. If it can get broken once it can get broken again.

As far as I understand that part of the code - it affects only popup message output, not the deconstruction and it's results.