Add support for downloading sbom via the platform 0.8 interface

[sambhav]

Description

Platform 0.8 in lifecycle uploads new sboms to a separate layer instead of a label. We should add support in pack to download this layer as a tarball.

Proposed solution

Describe alternatives you've considered

Additional context

• This feature should be documented somewhere

[aemengo]

As of v0.23.0, pack can now display the file-system of the build container. I think this would be a great feature, and workflow, to have as part of the terminal UI. What do you think?

[sambhav]

That sounds great, but I think we will still need to have a replacement for pack inspect-image --bom which works for both remote images and local images

[basit9958]

I would like to solve this issue. I am a beginner. Please give me some pointers as well as to what to implement and where

[dfreilich]

@basit9958 thanks for expressing interest! There is also already a PR open for solving this at the moment (#1351) , though, so we should be fine here

[natalieparellano]

Closing as #1351 was merged.