Fix: Add support for streaming data to mixins.apply_descrambler

[krapes]

This pull request merges a couple of fixes to the mixins.apply_descrambler. Specifically those from @giacaglia here and @FidoDidoVN here

It also adds a try - except case for videos that were failing because they didn't have a 'formats' in the stream_data json

[Armster15]

Following pull request breaks the length and thumbnail_url attributes

Sorry don't know where to post this issue but the following pull request, although it fixes mixins.apply_descrambler, it breaks the thumbnail_url attribute of the YouTube class and the length attribute. The following error logs are pretty much the same.

---

Error log for thumbnail_url:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python36\lib\site-packages\pytube\__main__.py", line 258, in thumbnail_url
    return self.player_config_args['thumbnail_url']
KeyError: 'thumbnail_url'

Error log for length:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python36\lib\site-packages\pytube\__main__.py", line 299, in length
    return self.player_config_args['length_seconds']
KeyError: 'length_seconds'

[krapes]

Hey, thanks for the update. Can you post the code you were trying to run when you got those errors?

[hbmartin]

@krapes @armaan115 you can pull in fixes from pytube3 for these issues

[Armster15]

LOL I just fixed the error as well, you guys can pull in the fixes: https://github.com/armaan115/pytube-568.git