[bitchute] add upload_date

[Nyaa-rlathotep]

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Description of your pull request and other information

Adding ability to grab "upload_date" from bitchute. Will probably fix #22990 as well.

[Nyaa-rlathotep]

Hold off on accepting this for the moment. Just discovered that date parsing fails on dates with "3rd" or "23rd" in them. Seems to work fine on "*th", "*1st", "*2nd", etc.

Here are some example URLs of failing ones:

(November 23rd, 2019)
https://www.bitchute.com/video/6GoIfm3Sd5cE/

(November 3rd, 2019)
https://www.bitchute.com/video/Sb9v8ax9B5rL/

I'll poke around a bit and try to figure out where the problem is.

Edit: Looks like a bug with "unified_strdate". I've submitted an issue about it over at #23197.

If you'd like, I can leave this pull request as it is and have it wait for #23197 to be fixed, or I could change this code so it removes the prefixes from the day of the month before passing it to unified_strdate if you don't want to figure out why unified_strdate is acting up. Whichever you all think is better is fine with me.

Edit 2: The issue with unified_strdate was a minor oversight with an easy fix. I've submitted a PR over at #23199. Once that one's checked over and verified and everything, this one can be checked for inclusion as well.