Updates for Particle and ParticleSystem for next stage

- [ ] deprecate all the start/end and max/min parameters in `Particle` and `ParticleSystem` and switch to using an init() function instead
- [ ] change how `Particle` handles updates since no longer lerping between start/end [ie removing the parts that do]
- [ ] update sandcastle examples to match these changes
- [ ] update [Particle System Tutorial](https://cesiumjs.org/tutorials/Particle-Systems-Tutorial/) and [Advanced Particle System Tutorial](https://cesiumjs.org/tutorials/Advanced-Particle-System-Effects/)

[actually maybe keep max/min elements for random initialization - TBD]

Start by inspecting the current Particle and ParticleSystem APIs and how the sandcastle examples use their start/end and max/min parameters. Review the Particle System Tutorial and Advanced Particle System Tutorial before deciding how initialization and updates should change. Done means the API behavior, examples, and both tutorials are updated, with the treatment of max/min resolved.

Written by the indexing model from the issue text.