player: supporting ANSI Sequence OSC-8 (hyperlinks)

[coxley]

If Asciinema is going for completeness, it might be interesting to support hyperlinks. The data is in the .cast files — just not interpreted in the display / rendering.

Details: https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda#the-escape-sequence
Example Cast: https://asciinema.org/a/MN2bkhHfqvSKK0hiKmnt46qq4

Snippet from the example .cast file:

# Second line: \u001b]8;;<url>\u001b\\<displayText>\u001b]8;;
[19.767998, "o", "\u001b]2;cs -r codesearch viper -f config --repos-only\u0007\u001b]1;cs\u0007"]
[20.203515, "o", "\u001b[35m\u001b]8;;https://github.com/coxley/codesearch\u001b\\coxley/codesearch\u001b]8;;\u001b\\\u001b[0m\r\n"]