occtet: Collect and federate raw registry/APIs metadata

[pombredanne]

• Collect and federate raw registry/APIs metadata
• For instance keep raw Maven POMs as is, including parents
• Or results of PyPI API calls
• Also Federated basic PurlDB package record, beyond just PURLs

[JonoYang]

thinking out loud:

1. create a new table to store pom content or api calls with foreign key to package its for
   • This would have a variable text field for content, file name, and date field for collection date
2. populate these tables when we visit upstream sources (in minecode pipelines or otherwise), e.g. in maven pipeline, when we process a pom for package creation, save the pom to the db
   2.1. update the minecode_pipelines to save metadata files it collects alongside the purl.yml files
3. when we federate packages to repos, also dump associated metadata files as well as purls