Java8获取当年所有日期 借用Java8中新增的LocalDate简单实现一年所有日期的获取，形如： 2024-01-01 2024-01-02 2024-01-03 2024-01-04 2024-01-05 2024-01-06 2024-01-07 2024-01-08 2024-01-09

List集合分组求和 适用场景 [{"name":"zhangsan", "grade":90}, {"name":"lisi", "grade":100}, {"name":"zhangsan", "grade":95}] => [{"name":"zhangsan", "grade":185},