Refactor cloud-init unit tests
Refactor cloud-init unit tests

Change the structure of Describe and Context containers to allow for
easier integration of tests for new cloud-init data sources and make
better use of BeforeEach blocks.

kubevirt/kubevirt,davidvossel/kubevirt,stu-gott/kubevirt,stu-gott/kubevirt,davidvossel/kubevirt,kubevirt/kubevirt,kubevirt/kubevirt,davidvossel/kubevirt,davidvossel/kubevirt,stu-gott/kubevirt,kubevirt/kubevirt,stu-gott/kubevirt