V1.1.0: Placement doesn't work from palette window unless palette overlay is enabled.

[FrayedFunction]

Description

Objects can only be placed when palette overlay is enabled, otherwise selecting thumbnails in the window does nothing.

Steps to Reproduce

1. Disable palette overlay.
2. Open palette window.
3. Attempt to place something.

Expected Behaviour

Visual placer should appear and selected object should be placed in scene.

Actual Behaviour

Selecting objs in the palette window doesn't enable placement.