Remove wrapping component `search_box`

The following discussion from !181 (merged) should be addressed:

• @winh started a discussion: (+2 comments)

  should we create a follow-up issue to delete components/base/search/search_box.vue? I currently don't see value in keeping it.

Let's remove the wrapping search_box.vue component and use the two underlying components directly.

/cc @winh