Accordion and Tabs paragraph need to be more accessible

Here's an initial patch with the proposed resolution.

A little update on issue #2. It only occurs if the accordion section doesn't have a title, which is very unlikely to happen if the element is being implemented correctly. However, the issue with the alt attribute and title attribute still needs to be addressed and that's why it's still included in this patch.

As for issue #1, I'm switching anchor elements to buttons, along with their respective styles.

I'm also including a fix to an incorrect validation of the default value for the title attribute in the twig template.

Updated patch for both the Tabs and the Accordion paragraphs. This fixes all the issues as described in the proposed resolution and adds some small extra changes, such as removing role attributes from places where they weren't needed.

Tested the patch and verified it works well! Ran it through lighthouse to confirm as well.

Automatically closed - issue fixed for 2 weeks with no activity.