Use the TV embedded client technique to get streams of embeddable age-restricted videos.
This client doesn't provide the playerMicroFormatRenderer object in the player response, but it is still returned on the WEB player response, even for unavailable (but non-private) contents, so we need now to store it, as we are replacing the player response from the WEB client by the TV embedded one.
Otherwise, some metadata such as the unlisted property, category, the uploadDate and the publishDate properties.
The outdated code for these contents has been removed.
Add the racyCheckOk and contentCheckOk to player and next requests to the InnerTube API.
The first doesn't seem to make any difference when used anonymously, but the second one is needed to get streams of contents with a warning before they can be played.
Also apply some requested changes, fixes and improvements in YoutubeParsingHelper and YoutubeStreamExtractor.
67288a0191