Update Icons

Subdivided the new icons in 3 size categories. As requested by UX
Used the company naming scheme for uniformity and easy recognition.

Known issues:
- Top/Bottom category wasn't taken into account by UX at the time. Since
 this is a recent addition. Both the Walls and Top/Bottom will be updated.
- Cloud/Network connection icons 12px don't render correctly. Due to the
 theme-ing.
- Extruder Icons do not render correctly.

CURA-8010_new_icons

plugins/PerObjectSettingsTool/PerObjectCategory.qml

@@ -24,7 +24,7 @@ Button {
                 anchors.verticalCenter: parent.verticalCenter
                 height: (label.height / 2) | 0
                 width: height
-                source: control.checked ? UM.Theme.getIcon("arrow_bottom") : UM.Theme.getIcon("arrow_right");
+                source: control.checked ? UM.Theme.getIcon("ChevronSingleDown") : UM.Theme.getIcon("ChevronSingleRight");
                 color: control.hovered ? palette.highlight : palette.buttonText
             }
             UM.RecolorImage