Tracking Issue: MVP Animation

This issue is meant to be a more actionable/scoped version of #91 and #95, specifically scoped to the goal of providing a minimum low level API for managing asset based animations in Bevy.

## RFCs
The overall design for these systems are detailed in the following RFCs. Later parts of the implementation are blocked on the design feedback on these individual RFCs.

- [ ] bevyengine/rfcs#49: Low level storage ans sampling design.
- [x] bevyengine/rfcs#51: Composition API and sampling strategy

## Implementation/Merge Strategy
This is a fairly large area that touches multiple core areas in the engine. Even with a complete prototype, introducing the system into Bevy in one large PR is likely difficult or impossible (see #1429). The following individual segments will likely need to be individually addressed to piecemeal introduce parts of the system into Bevy proper.

- [x] Assets: #3751
- [x] Assets; #3722
- [x] Rendering: #4238
- [x] Rendering: Rendering Morph Target Displacements
- [ ] Storage: Curve traits and basic concrete implementation (CurveFixed)
- [ ] Storage: Curve compression/quantization
- [x] Storage: AnimationClip Asset
- [ ] Storage: AnimationClip Serialization
- [x] Sampling: Basic skeletal animation player supporting start, stop, seek operations.
- [x] Composition: Basic AnimationGraph implementation.
- [x] Application: Skeletal animation application systems
- [ ] Application: General Reflect-based animation application systems