Make the image api more useful

- remove glance_id from the plan (a component will be used instead)
- add base_image_id, created_image_id & image_format to the image
- add source_format to the image
- choose the script path based on the image and source format
- pass the base image uuid into the build scipt

Change-Id: I89c01e84b0e38460c3a39ed7c9a3de22a0df49db
Remove unneeded from_db_object from image type

Change-Id: I01f46831ceab58e9bfc0a8ad600f504c464072e7