[feature] Document storage for transient docs (for both caching and long term storage)

[lumjjb]

Ask

In order to resolve #731, as well as to provide storage in cases where documents are emitted transiently (e.g. through CI), or for users who don't have a good metadata storage story, provide the ability for collectors to upload document blobs to a blob store (either caching - to meet #731, or for persistence).

Design document for this TBD, but most likely it will be a service that collector can talk to, and changing on the NATS pkg to point to the blobstore instead of sending raw bytes for bigger documents. This blobstore must be accessible by the ingestor as well.

Motivation:
This is to help address the use case of SBOM sharing, query and retrieval, i.e. I want to be able to retrieve SBOMs to help meet EO requirements or for others to request SBOMs for my organization software.

[lumjjb]

Decide to icebox this for now in favor of other proposed solution in #731