logs: adjust handling around partial log messages

In libpod/logs.LogLine.Write(), don't write a newline to stdout/stderr
when the log message is only part of a line.

In libpod.ConmonOCIRuntime.HTTPAttach(), don't send a newline over the
HTTP connection when the log message is only part of a line.

In pkg/api/handlers/compat.LogsFromContainer(), don't send a newline
over the HTTP connection when the log message is only part of a line,
and don't make doing so conditional on whether or not the client used
the docker or podman endpoint.

In pkg/domain/infra/tunnel.ContainerEngine.ContainerLogs(), don't add
our own newline to log messages, since they already come through from
the server when they need to.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>

pkg/api/handlers/compat/containers_logs.go

@@ -152,9 +152,7 @@ func LogsFromContainer(w http.ResponseWriter, r *http.Request) {
 		}
 
 		frame.WriteString(line.Msg)
-		// Log lines in the compat layer require adding EOL
-		// https://github.com/containers/podman/issues/8058
-		if !utils.IsLibpodRequest(r) {
+		if !line.Partial() {
 			frame.WriteString("\n")
 		}