cerbero: Add messages to cache command
cerbero: Add messages to cache command

This allows us to measure how much time each command takes with -t

Part-of: <https://gitlab.freedesktop.org/gstreamer/cerbero/-/merge_requests/608>

GStreamer/cerbero,GStreamer/cerbero,GStreamer/cerbero,nirbheek/cerbero,nirbheek/cerbero,GStreamer/cerbero,nirbheek/cerbero,GStreamer/cerbero,nirbheek/cerbero