BHV-1433: Prevent Marquee from overlapping higher zIndex controls.

Issue
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The `moon.Marquee` control will overlap a control with a higher `z-index` value (i.e. `moon.Tooltip`) when an element containing both controls has been transformed to slide the contents onto the screen.

Fix
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We set the `translateZ` value of `moon.Marquee` to `-0.1` when starting the animation. It appears that the transform applied to the containing element causes `z-index` values to be ignored until a `translateZ` is applied to the given element; the `translateZ(0)` applied to animate a `moon.Marquee` puts it at the top of the stacking context so instead we move it lower in the stack with a value of -0.1.

Notes
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Performed some basic benchmarking in the inspector on the TV and the change causes marquees to spend about 0.5-1.0% more time on scripting, rendering, and painting combined, which seems statistically insignificant.

Enyo-DCO-1.1-Signed-off-by: Aaron Tam <aaron.tam@lge.com>