Enable WMR motion controller visualization in editor playmode

[StephenHodgson]

Currently the WMR motion controller visualization is only availible after building the app. It would be beneficial to also be able to load the controller's visualization while playing in the editor as well. This implementation would ideally not use an external library imported into the editor

Migrated from https://github.com/XRTK/XRTK-Core/issues/40

Same as #9 But in the editor as well