TextInput context menu and a method for MVC data reperesentation

[cppdev123]

I noticed that among the limitations of current TextInput is that there is no context menu when right click on the text like any other text editor I've ever used before (also noticed that in slint) so I think text editing is something that is hard to achieve right in rust nowadays.

Another thing : Seems there is no any MVC widget in iced (ListView, TableView, TreeView) the ListView is the most important since tables and trees can be implemented as lists. Why MVC ? because it does not require you to provide the whole data to the widget each time in view method but rather store them once in a model and provide the model to widget and the widget will retrieve the visible items on demand, it looks like the difference between poll and epoll !