Add state to pull docker image

Add independent state to pull docker images,
so it can be executed separately from whole
docker.client state. In pipelines we can setup
parallel run for this state to make sure that
docker images are successfully pulled on each node.

Change-Id: Ic3417a97e3d34fb7c8bc695232eac24ad8cbae47
Related-bug: #PROD-25515 (PROD:25515)
4 files changed