integrate wave type classification

[rgutzen]

1. calculating velocity vector field (on amplitude or phase signal)
2. detect waves via VVF or via trigger times
3. classify and label wave types
4. filter for wave types

One key issue here is how to integrate the wave type classification in the wavefront_detection stage and how to combine it with the wavefront definition via trigger times.

[rgutzen]

[gulpgiulia]

(maybe issue #17 (this one) and issue #32 could be merged)

[rgutzen]

There hasn't evolved a general enough classification approach of labeling waves according to classes. Instead, the pipeline focuses on the characterization of the waves with measures such as planarity, which can be used to apply some custom wave classification on the pipeline output that is appropriate for the specific data and use case.
Furthermore, we integrated the block wave_mode_clustering that presents a general approach to wave type classification by clustering together similar waves into groups without the need to define or label these groups.

Closing this issue for now. However, the discussion if we want to include further wave-type classification blocks may be reopened in the future.