Curve as script property

**Is your feature request related to a problem? Please describe (REQUIRED):**
It would be great if a new field type such as ‘curve’ was added for scripts. To adjust them, we can use the existing UI from ParticleFX.

**Describe the solution you'd like (REQUIRED):**
`go.property("field_name", curve.linear(time_start, value_start, time_end, value_end))`
`curve.evaluate(self.field_name, t) -> value`
etc

**Describe alternatives you've considered (REQUIRED):**
Use imgui and create some in-game editor?..

**Additional context (OPTIONAL):**
I am currently working on car physics, and without visual curve adjustment, it is very difficult to achieve the desired result, i.e. I need to adjust how forces change as speed increases, and so on.

Curves also can be used to set custom animations for `go.animate`.

Also:
* https://github.com/defold/extension-simpledata/issues/17