[AnimateGamer] Add new extractor

[lcy0321]

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What is the purpose of your pull request?

• Bug fix
• Improvement
• New extractor
• New feature

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Description of your pull request and other information

Add extractor for 巴哈姆特動畫瘋.
巴哈姆特動畫瘋 is a anime streaming service operated by 巴哈姆特電玩資訊站 (a Taiwanese gaming forum) in Taiwan.

[lcy0321]

@dstftw
I make _extract_m3u8_format receive all the arguments (add: encoding, data, headers, query, expected_status) that _download_webpage_handle() needs and pass to it.
And make AnimateGamer extractor call _extract_m3u8_format() directly instead of my custom _extract_m3u8_formats_with_http_headers().

[lcy0321]

@dstftw
I notice that the parameters of _extract_m3u8_formats() I need was added in 7360c06
So I remove my change to that function in this PR.

Please review this PR if you have time, thanks.