Add support for aparat.com video sharing website

[MKaveh]

The website is https://www.aparat.com, an Iranian video sharing site.
youtube-dl shows this error when a link from this website is used:
for example for this url: youtube-dl --verbose https://www.aparat.com/v/N6Izi
this is the generated output:

[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['--verbose', 'https://www.aparat.com/v/N6Izi']
[debug] Encodings: locale cp65001, fs mbcs, out cp65001, pref cp65001
[debug] youtube-dl version 2020.03.24
[debug] Python version 3.4.4 (CPython) - Windows-10-10.0.19603
[debug] exe versions: ffmpeg 4.2.2, ffprobe 4.2.2
[debug] Proxy map: {}
[Aparat] N6Izi: Downloading webpage
ERROR: Unable to extract options; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; type youtube-dl -U to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.
Traceback (most recent call last):
File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmpjwbwqymm\build\youtube_dl\YoutubeDL.py", line 797, in extract_info
File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmpjwbwqymm\build\youtube_dl\extractor\common.py", line 530, in extract
File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmpjwbwqymm\build\youtube_dl\extractor\aparat.py", line 52, in _real_extract
File "C:\Users\dst\AppData\Roaming\Build archive\youtube-dl\ytdl-org\tmpjwbwqymm\build\youtube_dl\extractor\common.py", line 1005, in _search_regex
youtube_dl.utils.RegexNotFoundError: Unable to extract options; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; type youtube-dl -U to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.