QT Widgets Improvements

The project's aim is to improve GNU Radio's gr-qtgui component, which offers QT widgets for signal viewing. This project is broken down into a number of smaller projects, some of which involve adding new widgets like the compass display, MPEG display, and matrix sink, as well as strengthening the existing widgets by improving their code structures, making them more extendable, and reducing redundant code. The project additionally intends to enhance the gr-qtgui component's user interface by making it more understandable and user-friendly and by giving the user more power and customisation choices. In order to enable the creation of complete GUI applications from GRC, the project also entails the integration and support for QT Creator and QML design.