(cherry picked from commit ff442a6a)

Note:  `connectEditor()` is never called, and the signals it attempts
to connect do not exist.

Instead of resolving a name to a path and loading that into a QIcon get the icon directly. We know the icon will always be there so we don't need the error handling

This allows the icon being found without KIconLoader-specific code

Also prefer handling QIcon over QPixmap. This fixes the icon rendering on highdpi screens

It already pulled in by KParts, but we better not rely on that

When TimelineView attempts to get the user's preferred
calendar colors, it uses an empty preferences object, and the view
ends up using random colors for the time blocks.

Glen Ditchfield authored Apr 15, 2021 and Glen Ditchfield committed Apr 22, 2021

These changes match the changes to the master branch in commit de11c043.