(Bloomberg Opinion) — The Mid Valley Megamall in Kuala Lumpur has more than 100 restaurants, cafes, and snack stands to meet every kind of craving. As of this month, that list includes a novel and seemingly quixotic option: Santan, a cafe that serves airplane food in cardboard boxes.As restaurant concepts go, “quick airplane food” isn’t an obvious winner. But Santan is owned and operated by AirAsia Group Bhd, the region’s most successful budget airline. With profits declining in the industry, the company is looking to diversify — it wants to reduce flying from 80% of its business to about 40% […]