Embattled food and catering group Maxim’s, the focus of frequent vandalism by radical Hong Kong protesters, has rewarded its staff with a one-off bonus despite the city’s ongoing economic slump.The company on Monday gave HK$2,000 (US$257) to each permanent staff member and HK$1,000 to each part-timer as gratitude for their contributions during the past months of unrest, according to an internal letter the Post obtained on Tuesday.The letter, issued by chairman and managing director Michael Wu,…