* Avoid multiple initial data loads being issued by UICollectionView/UITableView
- Currently, there is a gap between the moment UICollectionView/UITableView triggers its first data load and when ASDataController finishes processing it. During this gap, the view keeps issuing "initial" loads by calling reloadData and causes its data controller to reload multiple times.
- Fix by immediately forward the first reloadData call to UICollectionView/UITableView before letting its data controller to handle it for real. During the gap, the view thinks that it loaded initial data but is empty, and thus stops triggering initial loads. Once the data controller finished loading, it will call another reloadData on the view which causes the view to swap to a correct state.
* Fix tests
* Use the existing flag of ASDataController
* Explain unit test
* New way to informing interaction delegate if ASCellNode get’s a setNeedsLayout call
* Remove nodeDidGetNeedsLayout as optional and better check if cell updates need to happen
* Differentiate between letting a normal display node and a cell node know that the size could have changed
* Check for _interactionDelegate is nil
* Add nullability to out pointer
* Adress comments and some renaming
Resolves#3037
This is a do-over of c85aa11, with the following differences:
- Fixed `_ASTableViewCell` properties **always** being mutated to match corresponding `ASCellNode` passthrough properties, even when the hosted `ASCellNode` is currently `nil`. Now only inheriting passthrough properties when there’s an actual instance of `ASCellNode` to read them from.
- Corrected spelling of `ASCellNode`’s `separatorInset` property.
- Reverted `_ASCollectionViewCell` inheriting the hosted cell node’s `backgroundColor` & `clipsToBounds` properties. This seems to be surprising and unwanted behavior to some, as seen in #3053 and #3044.
- Moved passthrough of `UITableViewCell`’s `selectedBackgroundView` into `_ASTableViewCell`’s `-setNode:` for consistency.
