Bhv 11591 Prevent unnecessary refresh() to increase performance

Issue
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Whenever user removes models from collection, `refresh()` is executed.

Cause
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If removing models are placed in current pages, `refresh()` should be called.
To decide it, we use `indexOf()` to get the first position of models.
However when we call `indexOf()` in VerticalDelegates,js, models are already removed from collection
So conditional statement for deciding `refresh()` makes wrong judgement.

Fix
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Get target index before model is removed from collection.
And deliver index info with `remove` event

Enyo-DCO-1.1-Signed-off-by: David Um david.um@lge.com
idx will not always be correct here because you're splicing elements out of the array. If the model were sorted by index (ascending), you'd be okay because you're iterating backwards through the array. If they're unsorted (or sorted descending by index), the indices will be wrong.