Data only in the leafs

[agcom]

Hold points only in the leaf nodes.

An option to switch between the default mode and this mode.

When this is enabled, the capacity field should be disabled.

This mode won't affect the time complexity, need more justifications on advantages and disadvantages of this mode.

[agcom]

https://stackoverflow.com/questions/60326475/should-quadtrees-store-points-in-subdivided-children-only