[ScrollControls]: add easing prop

[alvarosabu]

Description

As a developer using TresJS, I would like to be able to control the easing of the ScrollControl animation by passing either a value or an easing function myself.,

Suggested solution

We can set an enum of the most common easing functions

'easeIn`
`easeOut`
`power2`

etc

So a new prop called `easing` accept either a string from this enum of a function defining that easing function to be use

### Alternative

_No response_

### Additional context

_No response_

### Validations

- [X] I agree to follow this project's [Code of Conduct](https://github.com/Tresjs/cientos/blob/main/CODE_OF_CONDUCT.md)
- [X] Read the [Contributing Guidelines](https://github.com/Tresjs/cientos/blob/main/CONTRIBUTING.md).
- [X] Read the [docs](https://cientos.tresjs.org/guide).
- [X] Check that there isn't [already an issue](https://github.com/tresjs/cientos/issues) that reports the same bug to avoid creating a duplicate.

[damienmontastier]

Hey @alvarosabu, what about using Lenis to manage scroll controls? It can be cool if the website also work with Lenis! What do you thing ? Or maybe it's better to create another ScrollControls especially for Lenis, in case there's no height on our page and Lenis returns a height equal to the viewport.

[alvarosabu]

Hi @damienmontastier thanks for the suggestion! I didn't know about Lenis, it looks pretty good.

Normally we try to avoid adding external packages and since we handle almost everything with ready-to-go composables from @vueuse/core like useScroll which is reactive (we would need to make a composable wrapper around Lenis`

So it's unlikely we use it for cientos. That doesn't mean that you could try creating a package for Lenis as a Tres abstraction, we can support you on that. It would be the first community-based abstraction 😊

[damienmontastier]

Hey @alvarosabu , it's totally understandable and normal to emancipate yourself from a third-party library, it avoids any potential problems! Yes definitely, in the future it could be cool, we'll have to think about it! 👌

[andretchen0]

I've been working on Lensflare and needed some easing functions. I'm still working on approval with Jaime, but here's what's included so far.

For the moment, those easing functions are in /src/Lensflare/easing.ts. Would it be worthwhile to put them somewhere else? Maybe under /src/utils/easing.ts?