ENYO-643: Synchronize selection states.

### Issue
The various selection states (`multipleSelection`, `groupSelection`) were not being properly synchronized with the requisite `selection` state. This was evidenced in the `DataGridListSample` where enabling either multiple selection or group selection did not result in selection itself being enabled.

### Fix
We now set `selection` to `true` whenever `multipleSelection` or `groupSelection` is enabled. Additionally, there was a latent issue where subkinds that initially declared the `groupSelection` property would not have the appropriate logic run in the constructor as the property values had not yet been properly cloned; this logic was instead moved to `initComponents`.

Enyo-DCO-1.1-Signed-off-by: Aaron Tam <aaron.tam@lge.com>