Refactor to use Tween

[Jegber]

I propose a refactor of this codebase to use Tween, instead of the current usage of pow and lerp.

3 enhancements from using Tween that may be worthwhile:

• Use the whole assortment of tween transition types such as sine, linear, cubic, etc.
• Ease type such as ease in, ease out, etc.
• Duration of interpolation. The current interpolated camera only supports a speed value- this enhancement could support a duration value as well.

@Calinou I am submitting this as an enhancement proposal because I'm unclear about the philosophy of this addon. If it's meant mainly to recreate the old 3.x node's functionality, this enhancement may not be worthwhile. However if the "and more" is more important, this enhancement may make sense! Let me know what you think. I'm happy to submit a PR if this proposal is aligned with your vision for this addon. If not I'm happy to fork off of your awesome work!

[Calinou]

Feel free to open a pull request for this 🙂

Note that since the API is expected break compatibility, this will have to be released as 2.0.0.