Dish Network Corp. will close all company-owned Blockbuster video rental stores and end Blockbuster’s distribution of DVDs by mail, ending an era in which the brand dominated retail movie rentals. About 300 U.S. Blockbusters close by early January, the Douglas County company announced Wednesday. About 2,400 to 2,800 retail Blockbuster employees will lose their jobs in the shutdown, given the average of between eight and 10 employees per store. Dish (Nasdaq: DISH) purchased the formerly high-flying…