Add `DualFisheyeVideoAdapter` as a new adapter

[AntVil]

Describe the feature

Currently there exists a EquirectangularVideoAdapter and a DualFisheyeAdapter. I have a insv-file which is a video in dual-fisheye format. When i use EquirectangularVideoAdapter it gives me the incorrect result (obviously) and using the DualFisheyeAdapter i get an error that the adapter is not compatible for video.

As far as i can tell the changes to add a new DualFisheyeVideoAdapter, would be copy-pasting the EquirectangularVideoAdapter-folder and changing a few naming things and mainly this:

    constructor(viewer: Viewer, config: DualFisheyeVideoAdapterConfig) {
        super(viewer);

        this.config = getConfig(config);

-        this.adapter = new EquirectangularAdapter(this.viewer, {
+        this.adapter = new DualFisheyeAdapter(this.viewer, {
            shader: this.config.shader,
            resolution: this.config.resolution,
        });
    }

Alternatives you've considered

An alternative is probably to convert the video before-hand, for example by calling ffmpeg like described here: https://github.com/paulpaul999/vr-video-notes/blob/main/fisheye-to-equirectangular/README.md

though i don't really want to do that for my use-case

Additional context

No response