Set default zoom of AudioPlus

**Is your feature request related to a problem? Please describe.**

When using AudioPlus, long audio files start at minimum zoom level, which is impractical for annotation. Currently, every time a task is visited, the annotator has to manually hit the zoom button to get back to a more reasonable level

Is there any way to set the default zoom level of AudioPlus? Or to go back to the previous zoom level when reopening an AudioPlus task?

**Describe the solution you'd like**

It would be nice to be able to set the default zoom level of the AudioPlus, e.g., through a new `defaultValue` attribute.

**Additional context**

It would similarly be nice to be able to set the default speed of the AudioPlus.