Create fiber production factors

Creates one production factor per facility process in facilityProcessIds (at least one; duplicates are dropped), all for productCategoryId and with the optional minWastageFactorPercentage and maxWastageFactorPercentage (0 to 99.99; one left out stores none). The expected fiber loss is the midpoint of the bounds, or null without both (legacy stored NaN). An unknown category answers 404 product_category_not_found, a minimum above the maximum 409 invalid_wastage_factor_range, and a facility process that already has a factor for the category 409 production_factor_exists with none created (legacy answered 500). Responds 201 with the new factors in the order sent, in the { data, metadata } envelope (legacy answered a bare array).