Add support for generating an SBOM during image creation

Users working to secure their software supply chain need to track what packages, at which versions, are used in the environment to write and build and test their software. The dev container image as is the baseline for understanding this data about the environment. [Software Bill of Materials](https://www.cisa.gov/sbom) (SBOM) is the standard way to emit the information about what is in the image. It would make sense for the build step of dev containers image creation to have the option to output the SBOM for the image.