[SecondSpectrum] Meta Data Expansion

[UnravelSports]

Hi,

I've rewritten a small part of the SecondSpectrum tracking data parser to hopefully accomodate more meta data formats.

It works with the old data, but it now also works with a broader set of meta data.

I've introduced find_json_key() a function to search metadata a bit more flexibly. For example, some times "pitchLength" exists in the root, while other times it might exist in "Stadium"/"PitchLength". find_json_key will search for a value pitch length (disregarding capital letters) and then return the first found value.

I think an approach like this might be a way forward to allow for way more flexible metadata parsing.

In total my approach does:

• Search for pitch length and width
• Search for fps, if it doesn't exist, extract it from the first 25 frames
• Extract periods if they are in the metadata, if not parse them from the frames using self.__periods_from_raw_data
• Finally, we also construct home and away team values a bit more flexibly. I'm not 100% satisfied with this approach, but that's mainly because here structures and available information might be all over the place, but I don't know, since I've only got 2 different meta data files.

Eitherway, it should be a lot more flexible already.