Motivation

This PR is part of a bigger initiative to implement support for the new Smithy Protocol smithy-rpc-v2-cbor, as well as the new Botocore multi-protocol support for single services (before, a service could only define one protocol).

This PR is the first step in adding support for the smithy-rpc-v2-cbor protocol via our parsers and serializers.

By adding support for this new protocol, Botocore also implemented CBOR serialization and parsing. We can rely on that to implement our own custom body parsing/serializing in the CBOR format.

Currently in Botocore, only the services using the smithy-rpc-v2-cbor protocol uses this implementation (like arc-region-switch, and soon cloudwatch).

Internally, we know that the Kinesis service can respond using CBOR, but with a json-protocol based type of response. This PR implements and internalize the CBOR body parsing and serializing, and try to use this protocol to parser/serialize Kinesis requests & responses. In some follow-up to this initiative, we could also implement better handling of CBOR for Kinesis.

This PR is better reviewed by looking at its direct follow-up, #13125. It builds on this to properly implement the smithy-rpc-v2-cbor protocol entirely.

Changes

• internalize CBOR body parsing/serializing via the BaseCBORRequestParser and BaseCBORResponseSerializer
• validate that the CBOR serde works properly by trying it against our known Kinesis tests
• implements a CBOR parser based on the BaseCBORRequestParser and the JSONResponseSerializer to try out against Kinesis