Support demultiplexing comand streams (Docker attach protocol)

[clue]

Docker uses a multiplexed stream (unless TTY is enabled), we should demultiplex this into normal stream events. Either inspect or consider looking into response headers.

Affects:

• Add containerLogs API endpoint #12
• Add containerAttach API endpoint #13
• Add execStart streaming API endpoint #14

See https://docs.docker.com/engine/reference/api/docker_remote_api_v1.23/#get-container-logs

[clue]

FYI: Implementation is ready, I merely split this off in order to first focus on the main features here.