trs-image: add composefs
Tools to handle creating and mounting composefs images.
Flexible mechanism to support read-only mountable filesystem trees, stacking on top of Linux filesystem.
It will allow to enable filesystem integrity by leveraging the stack: ostree -> composefs -> fs-verity
For reference: https://github.com/containers/composefs?tab=readme-ov-file#filesystem-integrity https://ostreedev.github.io/ostree/composefs/#using-composefs-with-ostree
Signed-off-by: Fathi Boudra fathi.boudra@linaro.org