Suppress console warnings in CollectionView tests
Suppress console warnings in CollectionView tests

Some CollectionView tests were missing the initializeCell callback,
which resulted in a lot of warnings being logged to the console.

Set an empty initializeCell callback and add the missing event
properties to avoid follow-up errors.

Change-Id: I005baae5ba56467b0c47e8aa7aeb17492ef4097e

eclipsesource/tabris-js,eclipsesource/tabris-js,eclipsesource/tabris-js