Better Packs, Shapes, and Selections

[DonavinDraws]

-Pack Parsing now yields the appropriate shape for each actor
-Shape parsing consolidated into it's own function to avoid clutter
-Actors without a shape will still draw their models
-Updated ImGui.Net
-Ported the updated input method
-We can draw ellipses now
-Drawing actor bounds with better shapes
-Actors now show their translation point and square bounding box when selected
-Moving actors will account for the mouse's relative position to avoid jumping with bigger actors
-Revamp of the multi-select to allow moving multiple actors at once