BHV-668: Find and spot next/previous spottable item, generating additional pages as necessary.

Enyo-DCO-1.1-Signed-off-by: Aaron Tam <aaron.tam@lge.com>
ANG-10315 After recodes added, adjust pages if necessary.
In some specific case, moving down with 5-way key does not work
even though there are spottable items and page
This is because, list.metric does update after some records added.
It can be updated only after scrolling.

Before records added, dataGridList does not adjust pages event though focused item
passes scrollThreshold.
It is natural. behavior. There is no reason to adjust pages.

However if some records are added and it makes another pages to go,
adjusting pages is required.

Enyo-DCO-1.1-Signed-off-by: David Um david.um@lge.com
update naming scheme to not conflict or be confused with available public selection api

Enyo-DCO-1.1-Signed-Off-By: Cole Davis (cole.davis@lge.com)
Merge pull request #1411 from enyojs/ANG-10315-davidum

Ang 10315 Moving 5-way key does not work after records 

Reviewed-By: Cole Davis (cole.davis@lge.com)