Create a data object for sonified cubes

[stscijirahubjdat]

Issue JDAT-4991 was created on JIRA by Jesse Averbukh:

This will mean that the sonified cubes will act as layers in the image viewers, allowing us to use mouse over events independent of the spectrum-at-spaxel tool to trigger the sounds. This will also include having plot options know how to handle sound layers with some configuration options available in that plugin (slider for sound for each layer, ability to mute and unmute, etc.).