Types on SelectableObject don't include all types actually in object

[J-Gonzalez]

We're upgrading to the latest SeatsIO React lib.

We noticed that

<SeatsioSeatingChart
     onObjectSelected={selectSeats}
     onObjectDeselected={removeSeat}
     ...
/>

now enforces the type on these functions to be SelectableObject (which is great, because prior we had to define our own types here)

However, the SelectableObject typing seems to be missing some key items. Keys like "id", "numSelected", and others, but the keys are definitely in the object that gets called in the function.