Bhv 11099 Has improper position for disabled control.

Issue
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If tooltip is showing over disabled control, it could not calculate its position

Cause
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Current position calculation of tooltip is based on `enyo.Spotlight.getCurrent()`
However disabled control could not have spotlight focus. It makes problem.

Fix
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From `onenter` event occur, it preserves event sender and delivers it to `moon.tooltip`.
If `enyo.Spotlight.getCurrent()` is not existed, `adjustPosition()` will use preserved event sender

Enyo-DCO-1.1-Signed-off-by: David Um david.um@lge.com
Hi @DavidUM, this doesn't seem to work in the case of a standard `moon.Button` + `moon.ToolTip` where we disable the activator (i.e. disable any `moon.Button` in `moon.ToolTipSample`) as the sender is the activator itself. Should we modify this conditional's structure to account for that? Thanks!