Bhv 11576 Prevent unnecessary refresh() in DataRepeater.js

Issue
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When we remove some models from DataList, it makes another refresh() in DataRepeater

Cause
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Currently DataRepeater always execute refresh() whenever remove event sender is collection

Fix
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Decouple selection logic which DataList needed from `modelsRemoved` in DataRepeater.js

Enyo-DCO-1.1-Signed-off-by: David Um david.um@lge.com
Thank you @ryanjduffy and @clinuz 
I also agree with that thought.