“Spider-Man: Homecoming,” which zipped into theaters last weekend, is almost everything a summer blockbuster should be: It’s very funny without using humor as an excuse to be less than emotionally accessible; its super-sized throw-downs are anchored in real, human-scale conflicts; its world is richly populated with characters who aren’t solely defined by their powers or lack thereof; and it resists the urge to revisit the most famous story beats associated with its title character’s origin