Importer: Handle Additional Miscellaneous Media Types

Context

During the course of: &5523 (closed) some imports are failing due to unknown or unusual mediatypes.

Solution

We should investigate the following media types, and determine a course of action for each one:

• application/vnd.dsse.envelope.v1+json — DSSE — feat: add support for additional cosign media t... (!1035 - merged)
• application/json
• binary/octet-stream
• text/spdx - spdx
• /application/vnd.acme.rocket.config (leading slash intentional) — https://github.com/opencontainers/tob/issues/66
• application/vnd.acme.rocket.config
• application/vnd.vivsoft.enbuild.config.v1+json
• application/vnd.gitlab.packages.npm.config.v2+json
• application/vnd.spack.package
• text/plain; charset=utf-8
• application/vnd.gardener.landscaper.componentdefinition.v1+json
• application/x-yaml
• application/sap-cnudie+tar
• text/html; charset=utf-8
• application/vnd.acme.rocket.docs.layer.v1+tar