fix(storybook): transpile object-spread for Edge

What does this MR do?

Edge errors when loading storybook due to object-spreads used within bootstrap-vue and some stories.

This MR adds a webpack-loader to handle transpilation for all modules that use object-spread.

Note:

The loader is only added to the list of rules if NODE_ENV is not 'test'.

This is because the settings in 'babel.conf' target 'node' for tests, which is needed for jest but breaks the rendering of storyshots if the loader is applied.

Before

After