(gui): add notification dialog
Description
Notifications (as in web app) can greatly improve UI & UX in our applications.
Proposal
- First add a new kind of dialog (fwGui & fwGuiQt) to pop notification
- Several kind of notifications (SUCCESS, FAILURE, INFO, ...)
- Defines places where to display it (Corners of window, center...)
In a second time we may use a service or a manager to handle notifications and be able to stack them.