Periodic "ping" from long tasks in non-interactive mode

Currently if you're building something very slow like LLVM it gets hard to follow CI since it can't show the nice progress parts of Buildstream in non-interactive mode. It would be nice to have a periodic ping (eg Running build-commands) periodically over a long build, eg every 10 minutes, to be argued upon, so you know something is still happening (and which element it is that's building).

Since this behaviour is just noise in interactive mode, the ping should only ever be printed in non-interactive mode.