Extract movie parsers to separate library

[YoshiRulz]

To share code with TASVideos.org (see TASVideos/tasvideos#1529).

Besides the .bk2 parser, which is the reference implementation, the rest currently skip reconstructing the model and just convert straight to a Bk2Movie object. Many of the parsers are also missing features that were deemed unnecessary for the purpose of converting to .bk2 and resyncing.

Before starting on this, make sure you've familiarised yourself with both BizHawk's and TASVideos.org's parsers (and Bk2Exporter), and take the best of each.