Icons: Added star and folder icons

New Icons:
- wb-icon-star
- wb-icon-star-empty
- wb-icon-star-half
- wb-icon-folder-search
- wb-icon-folder-bookmark
This fixes #2374 by @cfarquharson after the spriting change in #2376
Merge pull request #2404 from nschonni/additional-icons-2374-fixup

Icons: Added star and folder icons