[icons] connect icon color to idl v2 library

[laurenmrice]

As-is

• The icon libraries each have their own copy of layer styles of the IDL color palette.
• When the icons are generated into Sketch from the plugin sync, they are connected to the black layer style in the icon library color palette (the copy of the IDL color palette).

---

To-be

• The icon libraries should not have their own layer styles. We need to delete them.
• When the icons are generated into Sketch from the plugin sync, they need to be connected to the black layer style from the IBM Design Language v2 library. You can download the library at Step 3 here. https://www.carbondesignsystem.com/designing/kits/sketch/#get-the-kit

---

*Note

• For inner fills: The plugin is currently doing this correctly and we just need to make sure that is carried over when we use the idl v2 black layer style.
• Inner fills are connected to the blacklayer style, but the opacity is set to 0%.