Improve localization of stock_locations/_form

In many, if not all, locales, the term "state" is translated by its geographical meaning, not as "condition, situation". This creates confusion, because users see this geographical term as a label to "state" checkboxes (active, backorderable default, propagate all variants) on stock location form. I changed the checkboxes group label to Status.

I also noticed that terms "backorderable_default" and "propagate_all_variants" are not translated, so I added them to locale file.