By Daniel Kline The fast-food giant has lagged behind its rivals in one very important area. Over the past few months, Wendy’s (WEN) – Get Wendy’s Company (The) Report added a strawberry version of its iconic Frosty to its menu and welcomed back the Pretzel Pub Burger and Pub Fries. It also brought back French Toast Sticks, and while none of these are radical innovations (a French Toast Stick appears to be a piece of French Toast cut up) they do keep things interesting for customers. Restaurant Brands International’s (QSR) – Get Restaurant Brands International Inc. Report Burger King has teste…