Cockpit-image-builder saves blueprint in ~/.cache, in a very specific format (including the image_requests/target information). This makes it impossible to reuse blueprints between the cockpit UI and the cli tools.

Possible fixes:

1. Add import/export to the on prem UI:
   1. Import both json format blueprints from the service and toml blueprints from cli (similar to what we do in the service currently)
   2. Export toml ideally, so composer-cli can use them (otherwise json can be fine too, ibcli can use those at least).
2. Store them differently on disk so the folders can be used more easily