E1482. Rewrite Project E1401

Project E1482 includes merging of E1453 and refactoring assignments_controller using a form object. We have made assignments_controller using form object. Please provide your comments
It is generally considered bad practice to assign params in the controller. They are coming from the view as parameters (almost) to the controller action. It's similar to the following:

```rb
def five(x)
  x = 5
end
```