Support audio tweening

[Multirious]

hmmmm

Well, this crate could tween anything, so might as well gives audio a try. Not exactly sure how to approach this yet but it would be funny.

bevy_tween already supports parallel of interpolating things from start to end. Well, audio does have a start and an end, we should be able to tween that!

[Multirious]

• Maybe make a fork out of bevy_kira_audio that uses this crate's tweener as the player, assuming I can't make a patch to interface between these 2 crates.
• After check the code a bit, the clock and tweens is already inside the kira crate it self so I might need to fork that too.
• A channel could be an asset like in the original or... another entity 🤔.
• Fade in and out is simple as another tween.
• The audio likely would be a component with handle to audio to stores additional settings like volume and panning.

Is this insane?

[Multirious]

Closed as it should be its own crate