Fixed "get_throttling_function_name: could not find match for multiple" and other improvements

[felipeucelli]

Fixed "get_throttling_function_name: could not find match for multiple" #93

Recently YouTube updated its base.js and broke our regex that found the throttling function.

Example of the old structure:

a.C && (b = a.get("n")) && (b = Bpa[0](b), a.set("n", b)

New structure::

a.D && (b = String.fromCharCode(110), c = a.get(b)) && (c = IRa[0](c), a.set(b,c), IRa.length || Ima(""))

YouTube also added String.prototype.split.call to the throttling function.

This PR updates the regex to match the new structure and adds a command block in jsinterp.py to interpret "String.prototype.split.call".

Other improvements

YouTube also removed the use of API keys in its requests, so we updated the innertube structure.

[Deslakator]

Just change chipper.py and it's works for me, thanks for your PR

[felipeucelli]

YouTube, in addition to changing the regex, also changed the structure of the throttling function, so just updating cipher.py will only fix clients that do not require decryption.

Just change cipher and run for example:

yt_url = 'https://www.youtube.com/watch?v=60ItHLz5WEA'
yt = YouTube(yt_url, 'WEB')

for y in yt.streams:
    print(f'{y} : {y.url}')

And you will have:

pytubefix.jsinterp.JSInterpreter.Exception: Unsupported String method prototype.split.call in: String.prototype.split.call(a,"")