Blender Git Loki

Fix T54286: bpy.props operator example misses property access

The old example had two downsides:

- It promoted a blocking UI design, where the user is shown a popup
before actually executing the operator.
- It didn't show how to actually use the property values.

The new code avoids these mistakes. The properties are also shown in the
redo panel in the 3D view.

Note that I also changed the bl_idname, as this is an example about
properties, not about dialogue boxes, and changed the class name to use
the standard operator naming convention.

I also extended the example to include a panel that sets multiple
properties of the operator, since I see questions about this relatively
frequently.