`rofl build`: Warn, if .orc size and images to be fetched is greater than `resources.storage.size`

[matevz]

A common mistake is leaving the default 512 MB storage size in rofl.yaml while compose.yaml will fetch images with bigger size in total.

1. Detect the size of images to be pulled during startup and warn the user that resources.storage.size will be too small to accommodate them. This is also a good check that the images are really publicly available to download.

2. Also, when checking the image size, also check, if the platform of the Docker image is linux/amd64. See rofl-docs: Add "unknown enclave" and othe ROFL-specific errors on the node to troubleshooting oasis-sdk#2160 bullet 5.

3. Also, try to fetch all images in compose file to make sure they are publicly accessible.

[matevz]

Unblocked by #422