Refactor/cleanup paints and animated profile pictures

[Nerixyz]

Description

Paints

• Uses const & where possible
• Fixes clang-tidy warnings
• Avoids allocating QGraphicsDropShadowEffect on the heap

Animated Profile Pictures

• Uses QObject hierarchy to manage deletions

[Nerixyz]

We should think about using a QGraphicsScene to draw the graphics effects. Not sure if it's less expensive than a QLabel, though.