use WEB_CREATOR when po_token with WEB_EMBED as a fallback

[unixfox]

This is a continuation of the work done in https://github.com/iv-org/invidious/pull/4923

• This uses WEB_CREATOR client for fetching the streams data when po_token is configured. Thanks @rustynail1984 for the notification
• WEB_EMBEDDED_PLAYER is configured as a fallback for po_token in case WEB_CREATOR doesn't work anymore
• Since neither WEB_CREATOR nor WEB_EMBEDDED_PLAYER returns microformat data, I have configured so Invidious does not crash if it doesn't find it anymore. This means that we will be missing some info until we switch the retrieval of this info from the next endpoint.
  But this is better than nothing that works.
• TvHtml5ScreenEmbed won't be used when po_token is configured since it doesn't work with it.

[rustynail1984]

Found the latest verion in YouTube Studio.

clientName:  62 // corresponds to WEB_CREATOR
clientVersion:  "1.20240918.03.00"