Implement Direct Upload of Binary Content at the Binary Endpoint

[allentiak]

Specification:

• When binary data is written to the server (create/update - POST or PUT), the data is accepted as is and treated as the content of a Binary, including when the content type is "application/fhir+xml" or "application/fhir+json", except for the special case where the content is actually a Binary resource.

Scaffolding:

• Check the blaze.middleware.fhir.resource middleware. There, we also need a wrap-binary-resource function that has to allow non-fhir content-types and will create a Binary resource on the fly using the body as :data (base64 encoded, of course) and adding the content-type as :contentType.

• At the end, both moddleware functions, the already existing wrap-resource and the new wrap-binary-resource have to emit a FHIR resource to the next middleware/handler.

• We will also need integration tests for this feature. In order to implement them, we can use the openssl command like in .github/scripts/generate-large-binary-resource.sh to generate such a large 8 MiB random content for the integration test. We should be able to upload and download that content and it should be equal afterwards.

Part of #2009.