a scrollPhysics for config refresh scroll effect,enable viewport out of edge whatever physics it is
in ClampingScrollPhysics, it doesn't allow to flip out of edge,but in RefreshPhysics,it will allow to do that,
by parent physics passing,it also can attach the different of iOS and Android different scroll effect
it also handles interception scrolling when refreshed, or when the second floor is open and closed.
with SpringDescription passing,you can custom spring back animate,the more paramter can be setting in RefreshConfiguration
This is the most important component that provides drop-down refresh and up loading.
RefreshController must not be null,Only one controller to one SmartRefresher
