fx(params) color option to disable opacity (alpha) picker

[Paul-Browne]

The option for opacity when picking a color might not be wanted, esp. if there are multiple color selectors and some global opacity param for a project.

Something like...

  {
    id: "background",
    name: "Background color",
    type: "color",
    default: "BADA55",
    options: {
      opacity: 0.5,           // default 1
      opacityPicker: false    // default true
    }
  }