Port guides, notes, etc. away from QQuickPaintedItem

[mitchcurtis]

Where possible, we should paint via Qt Quick primitives to improve rendering performance.

• [x] Guides.
• [ ] Notes.
• [ ] Rulers? Might be too much work.
• [ ] TileGrid.
• [ ] SelectionItem?
• [ ] RectangularCursor? Probably not inefficient enough to make a difference.
• [ ] SelectionCursorGuide.