feat: ClientObjectsSpatialHashing

[PrincessLunaOfficial]

Allows SpatialHashingInterestManagement to include NetworkConnection.clientOwnedObjects into grid projection checks.
It allows player to leave his pet anywhere and all entities around pet are considered IsWorthUpdating().

[MrGadget1024]

clientOwnedObjects includes the primary player object, so this needs to be reworked as:

if (projectNearClientOwnedObjects)
{
    foreach (NetworkIdentity clientOwnedObject in connection.clientOwnedObjects)
    {
        Vector2Int clientOwnedObjectPosition = ProjectToGrid(clientOwnedObject.transform.position);
        grid.Add(clientOwnedObjectPosition, connection);
    }
}
else
{
    Vector2Int position = ProjectToGrid(connection.identity.transform.position);
    grid.Add(position, connection);
}

[miwarnec]

will keep it open to remember to reopen another PR. this one misses OnCheckObserver check

[miwarnec]

closing as this is 3 years old