feat(SBOMER-225): Adjust bom-ref for container image manifests

[vibe13]

No description provided.

[goldmann]

I think the problem with this approach is that it will get out of sync after the DefaultProcessor is run. In most cases we will update the purl to the new value, but bom-ref will stay as it is.

At the end of the day we will suggest that it is a purl, but in fact it isn't, because a purl of this value will not exist anymore.

[goldmann]

I like to think of bom-ref as an identifier in the database sense, a random string. I know you don't agree with it, so we can use purl, but it needs to be consistent if we decide to do it this way.