Future: widgets with parameters as tuples

[forrestbao]

Currently we are dealing with only one widget with parameters, which are sliders. In the future, it's every likely many other widgets will have parameters, such as textareas which have attributes like number of lines or width.

Hence, we need a solution to parametrize widgets.

Below is the brainstorming result of me and Yazawazi tonight.

@funix(
    widgets = {
         "x":("slider", 
               {
                "start" : 10,
                "end"   : 100,
                "step"   : 4
               }
            )
    }
)
def bar(x:int) -> int:
    return x=1

@funix(
    widgets = {"x": ["sheet", ("slider", {"start":10, "end":100, "step":4})]}
)
def f(x: List[int]) -> List[int]:
    return x

[Yazawazi]

Done in https://github.com/TexteaInc/funix/commit/5863e08d31eb995ee8621fd0c5d03647d4e8ccd5