Add `viewComponents()` to use the component map/model loading functionality.
Add `viewComponents()` to use the component map/model loading functionality.

When a `components.js` file exists it used to map from package name to STL
model file path. This is then used to populate footprints with the correct
component model, if the model exists.

(Note: No `components.js` file is yet committed.)

Omniblox/Eagle-Loader,Omniblox/Eagle-Loader,Omniblox/Eagle-Loader