Progressbar should be aligned with start/end offsets

[xenji]

The records do have the absolute offset available. One could spin up one PB per partition and use the delta between start and end offset as range and the absolute offset progress from the single message as position.

[xenji]

All present progressbar implementation suffer from the same issue: MultiBars cannot be used without threads. To achieve a realistic display of the progress, each partition must be displayed individually. Therefore, this ticket sleeps until https://github.com/mitsuhiko/indicatif/issues/33 is solved.