fix water cannot set the position in .scn file and add the foam effect

[tcm390]

Add the foam to water and fix the bug that water could not set position in .scn file. And I found that in order to fix the frame issue of the foam effect, I need to render the foam render target in webaverse-render-pass.js Sibling: https://github.com/webaverse/three/pull/18 https://github.com/webaverse/water/pull/5

result:

https://user-images.githubusercontent.com/60634884/180922893-ab5b194f-4f19-4216-bc02-14127a5a5ed5.mp4