Remove direct external access to `IDrawableObject`s

[ShrimpCryptid]

Use Case

Currently, clients create their own IDrawableObject objects and pass them into vole-core. This causes us to depend on three's API externally.

Ideally, we should instead have vole-core manage its own objects, and users would just pass in settings objects to update them.

Solution

• Remove view3d.addObject and related methods.
• Clients should call view3d.addObject(type, data) and receive a typed handle back.
• Clients can update via view3d.updateObjectData(handle, data).
• Clients can remove objects via view3d.removeObject(handle).
• Change IDrawableObjects to have single updateSettings(), which has no three types.

Alternatives

Consider typing the handles and the settings objects?

type LineHandle: `L${number}`
type ArrowsHandle: `A${number}`
type SpheresHandle: `S${number}`

type HandleToSettings = {
   [LineHandle]: LineData,
   [ArrowsHandle]: ArrowData
}

view3d.updateObjectSettings<T>(objectHandle: T, settingsToUpdate: Partial<SettingsOfType<T>>)