New intensity track w/ layers. Keep the sounds of 'being in deep shit' varied as much as the smooth sailing tracks

[Solbusaur]

We have a nice selection of soundtracks now for smooth sailing, but when intensity starts to pick up, it's the same layers and base track we've had for over a year. Would be satisfying to hear something else when I'm drowning in monsters and water. If we can get multiple tracks that pick up with increasing intensity, high difficulties won't sound so repetitive.
In addition, whereas smooth sailing tracks have a lot more tune, the intensity layers have always been more soundscape-y and percussion filled. It should be kept consistent with the new ones too