"smooth_damp" functions for primitives and math structs

## What problem does this solve or what need does it fill?

I need to smoothly move a value towards a target value over time using velocity and other parameters (see below).

## What solution would you like?

I would like a set of "smooth_damp" functions for primitives and which have:
- current
- target
- velocity
- smooth time
- max value delta
- time delta

Importantly, I would also like a *spherical* smooth_damp for Vec2 and Vec3.

## What alternative(s) have you considered?

A similar effect can be achieved using interpolation functions while updating the start value. However, this lacks all the parameters of a smooth_damp function.

## Additional context

https://docs.unity3d.com/ScriptReference/Vector3.SmoothDamp.html

The issue names no files or tests; start by reading the linked Unity Vector3.SmoothDamp reference and locating Bevy's existing interpolation functions for primitives, Vec2, and Vec3. Done means adding smooth_damp functions with the requested parameters, including spherical variants for Vec2 and Vec3, with behavior covered by appropriate tests.

Written by the indexing model from the issue text.