Don't reference test asset projects in Build.props (#39336)

- test projects should include any necessary references
  - should further reduce build ordering problems
  - also, removes mention of a few non-existent folders
- but, special case a _few_ test asset projects
  - reference three used in test classes in relevant test projects
  - reference five that are otherwise unreferenced in Build.props
- move `src\Components\Web.JS\node_modules` mention to correct part of Build.props

nit:
- sort "not meant to be built" project list