Support user-provided custom SerDe

[weeco]

Users should have a way to write and use their own SerDes for serializing or deserializing messages when producing or listing messages via Console. Use cases could be:

• E2E message encryption
• Custom serialization strategies with common formats (e.g. storing protobuf metadata in headers instead of the key/value payloads)
• Custom formats (e.g. [Feature Request] REST serde #1177)

To achieve this we could potentially utilize Go's plugin system (which has a several downsides such as missing Windows support though), Hashicorp's plugin framework or WASM.