Place Actor Palette control

OmniToolbox provides 2 ways of adding any actor to Unreal's Place Actors panel.

1. Through the Omni_AddActorToPlacementPaletteCategory macro in C++

2. Through the OmniToolbox project settings, which is primarily used for blueprints.

You can then define your own categories in C++ like so:

Omni_PlacementPaletteCategory(
"Agent Intelligence Framework", /*Category name*/
"AIF", /*Display name*/
"EditorViewport.VisualizeVirtualShadowMapMode", /*In-engine SVG icon*/
0); /*Order priority - higher number means = closer to the bottom*/