PR to handle vm images for create vm scenarios

Changes in the PR include
1. Support for creating virtual machine using vm images.
2. Support for creating docker vm using vm images.
3. Image Show & Delete Image would now delete vm images.
4. Support for A8,A9 role size for create vm.
This routine is a utility function that checks if the specified image name exists as a VM image and/or an OS image (or neither). It is up to the caller to decide what will be done in response to the output that this function produces. At this point, this is called from `deleteImageInternal` in **deleteImage.js** and there it does treat it as an error in case the image exists both as a VM image *and* an OS image.