Add a new `compatMode` parameter to libpod's pull endpoint. If set, the
streamed JSON payload is identical to the one of the Docker compat
endpoint and allows for a smooth integration into existing tooling such
as podman-py and Podman Desktop, some of which already have code for
rendering the compat progress data.
We may add a libpod-specific parameter in the future which will stream
differnt progress data.
Fixes: issues.redhat.com/browse/RUN-1936?
Signed-off-by: Valentin Rothberg <vrothberg@redhat.com>
8b46e852ef