Main CL: 1. Copy the code from BE to implement the `str_to_date()` function in FE. 2. `str_to_date("2020-08-08", "%Y-%m-%d %H:%i:%s")` will return `2020-08-08 00:00:00` instead of `2020-08-08`.
The error format '##keyword' in a lot of docs. This pr is to repair document format. #4335
