Kanban board: accordion headers are coded inappropriately.

Issue Summary

Accordion headers are coded inappropriately in the issue details view.

Steps to Reproduce

1. Navigate to the kanban board page.
2. Open any issue details view.
3. Inspect the code of accordion headers such as "Details", "Description", etc 
4. Observe that the button & heading are coded separately.

Actual Results

The accordion headers such as "Details", "Description", etc are coded inappropriately. The <button> & heading elements are coded separately. This is not according to the specifications of APG guidelines.

This makes screen reader users difficult to access the functionality effectively.

Note: this issue is also applicable on the issue view page.

Screenshot

Expected Results

The accordion headers should be coded as per APG guidelines. The <button> element should be wrapped inside the heading <h3> elements. 

Ensure that all the accordion headers such as "Details", "Description", etc are coded as per APG guidelines for accordions. 

Code snippet:

<h3>
 <button><svg>...</svg>Details</button>
</h3>

Refer to the APG Example of accordion: https://www.w3.org/WAI/ARIA/apg/patterns/accordion/examples/accordion/ 

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available