Refresh items on content change

[FCalabria]

This will check if the content of the arrays has changed, even if the number of items displayed stays the same, and update them in that case.

[legeneek]

some points need to check:

1. call equalArrays without this may cause error
2. computeDisplayItems will be called frequently, should avoid heavy computation in it
3. this component may assume the item's content will not change, the index check is used to avoid unneeded computation. if you want to track the change of item while index stays the same, simply remove the index check can work
4. you can run 'npm run dev' to test you code