Implement image query by tag

Sometimes, user want to query images by tag since it's an
intuitive way to distinct different image. The REST API
would be like: v2/images?tag=x86&tag=64bit

docImpact
Implement bp image-query-by-tag

Change-Id: I42946fa838ed896823e17fd4c51995209d9d2ad3
Merge "Implement image query by tag"