Added JSON reporting capabilities

[BBerastegui]

I added JSON output in the report.

It will drop the file with the output in the same directory as the aquatone_report.html but with filename aquatone_report.json, pretty-printed and indented with 4 spaces.

[BBerastegui]

Sorry, but I also added in the same PR one small modification in the HTML of the report 😇

[0xdade]

I would love to see this feature implemented in aquatone. JSON output allows for a more structured approach to parsing the output of the tool, in a way that is a bit more valuable than only raw lines. I'd love a json document that gives me the relative filename of each document as well as any metadata about it. That said, I think it should be an optional flag and not necessarily included in the default output. But either way, I'd just love to have json output.

[joanbono]

Hi @michenriksen , any plans on having this added?

It would be awesome to have this json output