Allow use of field value to populate alt text
Currently, alt text on any visual is populated by static text entered by the report designer. It would be more helpful to be able to use a field value or do something like the Enlighten Data Story where you can put a placeholder for multiple field values. Ideally, the alt text on a visual provides a summary of what you should glean from the visual, which could change as data is refreshed. So we need a way to dynamically populate the alt text property.