[Bug] Invalid HTML when using the global search and accessibility issues

[ChristineLamontagne]

Describe the bug
Create a table with the ShowSearchBar="true"

the generated HTML ends up with

        <thead class="thead-light text-dark">
            <tr style="cursor: pointer;">
                        <th scope="col" style=" user-select: none" ondragover="event.preventDefault();" draggable="False">...

Expected behavior
I expect a valid and accessible html. Only one Thead is allowed in a table , images must have alt tags (the clickable image for filtering) and actions such as clicking on the header to order by that column should have an explanation.