Have a clear report of the extraction process

[vlaci]

It should be different from the logs. Log information should go to a file by default. A human readable summary should be displayed on the standard output.

We want to have different outputs:

• reporting (summary of extraction, valid, invalid chunks etc.)
• logs (already there, but should be written in the file)
• metadata (extracted file info, information on the content) -> Metadata file #16

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Scope of this ticket:

• console report of identified chunks and encountered errors
  • summary (aggregated results)
  • amount of valid (by type) & unknown chunks (also the size of the chunks)
    • number of extracted files by type
    • depth of the chunks
    • hints on unknown chunk (eg: encrypted)
  • any error we encountered during handling & extraction
  • have a non-configurable output by default and we can change it later if we feel it is too verbose
• store the logs in a file as well instead of dumping log messages to the console (should be configurable)

[martonilles]

We want to have different outputs:

• reporting (summary of extraction, valid, invalid chunks etc.)
• logs
• metadata (extracted file info, information on the content)

[qkaiser]

Fixed by #567