Investigate QJsonObject for JSON support?

[ferdnyc]

I happened to notice over on Launchpad that a user had submitted full patches for libopenshot to use Qt's built-in JSON support, QJsonObject, instead of relying on Json_cpp.

They're from 2015 so they're a bit out of date, but the concept seems sound. And the really interesting thing about the idea is, in addition to eliminating a dependency, QJsonObject is supported in PyQt5, which means openshot-qt and libopenshot could be using the same library to manage JSON data. I can only imagine that would be a win.

Qt manages the JSON data in what they claim is a highly-efficient binary form, with QJsonDocument being used to convert back and forth to a text representation.

[RichiCoder1]

Endorse. I'd be willing to undertake this. json_ccp has some extremely problematic problems in our integration when doing things like custom effects.