Remove unused imports from Lib

Some are not reported by PHPStorm, I found them with a regex.

Change-Id: I0fb8866935c073339b150ac45b27934d0fd94c17
Extract FormatterLabelLookupFactory

Change-Id: I9fa6c6baa7eb5d4893fb2dd8554d27dd7047eb6f
Move {Entity,Property,Item}View to Wikibase\Repo\View

Change-Id: I42cdba5ccd507a530fd9a56cda29739577994da3