Fixed #788: Encode/derive case classes as UniformBlocks

[davesmith00000]

The main goal of this PR is to drastically improve how easy it is to send data to shaders. We've gone from having to know about all of this:

ShaderData(
  Shaders.externalId,
  UniformBlock(
    UniformBlockName("CustomData"),
    Batch(
      Uniform("ALPHA")        -> float(0.75),
      Uniform("BORDER_COLOR") -> vec3(1.0, 1.0, 0.0)
    )
  )
)

...to a very familiar this:

ShaderData(Shaders.externalId)
  .addUniformData(CustomData(0.75, RGB(1.0, 1.0, 0.0)))

final case class CustomData(ALPHA: Float, BORDER_COLOR: RGB) derives ToUniformBlock

The conversion process supports all the same types we used to support, but now we don't need any specialised syntax - WHICH MEANS - all the old imports for shaders have gone - WHICH MEANS - no more term/import collisions with Ultraviolet!! 🎉

Additional clean up work done in this PR:

• Deprecates BlendShaderData
• Removes all shader primitives from the default import
• Removes import indigo.shaders.* - not needed
• Moves ShaderData to live with Shader classes, rather than Material classes
• ShaderData no longer unnecessarily extends Material