The origin of this PR was a strange munmap_chunk(): invalid_pointer that started appearing in our GHA CI.

This error only appeared during code generation, and after narrowing it down a bit further, it seemed to happen during destruction of the S3 API.

Having AWS C++ SDK as a dependency just to interact with out MinIO S3 server always felt like an overkill. In addition, the SDK's init/destruction lifecycles have always been sketchy and error-prone. We were not using the SDK according to its guided usage neither. All in all, it felt reasonable to ditch such a heavyweight dependency and, instead, use MinIO's native C++ client.

In the process of doing so, a rather gnarly bug appeared in the interplay between libcurl (as used by MinIO's CPP client) and cpprestsdk. Turns out this is a known issue with cpprestsdk.
Alas, the project is EOL-ed, so I also ditch the dependency and make our HTTP servers inherit from faabric's native HTTP handler base class.

Unfortunately there is a cyclic dependency between both contributions that prevent me from breaking them into two PRs:

• We need to get rid of AWS SDK C++ for the codegen step in the CI to not break.
• We need to get rid of cpprestsdk to get rid of AWS SDK.
• We need the CI to not break to get rid of cpprestsdk.