Better align component selection UI with Drupal core styles

The current UI for the component selection is fairly close to the new field selection UI, but some work should be done to make it more consistent and accessible.

The current UI

Field selection UI

My thought is that a vertical card makes sense in this case (unlike the field UI), but focus styles, colors, drop-shadows, etc should align. Also note that the field UI will likely have some minor changes done in 🐛 Adjust design implementation for the field types Fixed