Accessibility issue with alt text on background image for column block

[NicktheGeek]

This was reported initially during an accessibility audit we were running against a new project. At first I thought it was a human error but with subsequent tests it appears to be an issue in the block output. This could potentially be a user/documentation error though.

Repro steps

1. Insert a grid block
2. Set a column to have a background image
3. Check the HTML of the <img> tag to verify there is no alt tag.

Attempted fixes

1. Initially the alt tag was not provided in the background image vis the media library. The Alt tag was added and the image was updated in the column background. No alt text was added.
2. Checked to see if there was a method for adding the alt tag to the background image but it was not readily apparent.

Expected Results

1. The alt text from the media library would be used for the background image.
2. A field would be provided or made clearly available/documented for adding a custom alt text for the background image.