feat(anlz): Add Support for 3-Band Waveforms

[FizzyApple12]

This PR does the following:

1. Adds Waveform3BandPreview, Waveform3BandPreviewColumn, Waveform3BandDetail, and Waveform3BandDetailColumn structs based on the information here and here
2. Adds Waveform3BandPreview (magic PWV6) and Waveform3BandDetail (magic PWV7) to ContentKind
3. AddsWaveform3BandPreview and Waveform3BandDetail to Content
4. Cleans up a the documentation around the Waveforms to make the comments point to the correct links and have consistent descriptions

[acrilique]

Hi! I just left a couple of comments. Feel free to address them while you wait for a review by someone with write access.

[Swiftb0y]

It would be nice to have some tests for these to ensure stability. We already have some .2EX files in the complete_export dataset.

[FizzyApple12]

The existing parsing tests that exist for anlz pass with this code, if there's interest I can make some more that test parsing individual parts of the data in the files though

[Swiftb0y]

Ah right, anlz has no unit tests, only a basic read-write integration test.

[Swiftb0y]

LGTM. Thank you.

[FizzyApple12]

Of course! I'm glad to contribute!