make backup Stream of all waveform data only after all cleanup operations
cleanup (remove last remainders of old dictionary structure for
event metadata)
fix labels in stream overview
some adaptions for seiscomp automatic events:

- picks by scautopick don't have location codes, so do not match against
  location code when selecting picks
- don't try to plot amplitudes, they do not store the exact times where
  the picks were set but only a big time window that includes the
  complete waveforms