feat: add script to create security manifest

[alesancor1]

Wrapper script uses the chisel wrapper to generate a security manifest based on dpkg status.

Usage: security-manifest [OPTIONS] -- <slice names..>
Example: security-manifest --cleanup --rootfs myfs -- --release ubuntu-20.04 libc6_libs

[cjdcordeiro]

thanks for this :)

before looking at the code, could you please move the script into a dedicated folder? The chisel-wrapper ended up at the root level just because it was the first one and and the sole reason why we created this repo, but all the subsequent tools ended up having their own folder.

P.S. it would also be nice to have a PR description. This is useful for the future, if ever we need to come back to this PR and try to understand the context and motivation that led to this change.

[alesancor1]

From @cjdcordeiro:

The Fetch Service will be enabled in the OCI Factory soon and it will produce a manifest that includes all sw components, including slices.

This means we can use such manifest to create the dpkg.query manifest for security. The input may be different so the script I created will need some tweaks. The script should be wrapped into an action afterwards.