[server] replace native django route /results/{uuid}/json/ with a DRF api/results/{uuid}/json/

[Tointoin]

@gnuletik @yomguy

• api/results/{uuid}/json/ should return the entire content of potential result's hdf5 file. A subprocessor_id query param could allow to choose part of the content. A custom filter (as for ItemWaveViewFilter) could allow to describe hdf5 content structure in the schema.

• another route may allow to provide hdf5 file content with start/stop and nb_pixel query params as for waveform, for under sampling on the backend side for zooming purpose. Particular focus has to be given to the multiple potential data types on the y axes (e.g. a column of value for a spectrogram, e.g. a single value for an onset detection or no y axes for a full track value or potentiel labeled data instead of numerical values).

[gnuletik]

Yes ! That would also help for the docs / schema / SDK because native django routes are not available in the schema.