🔇 fix: Hide Button Icons from Screen Readers (#10776)

If you've got a screen reader that is reading out the whole page,
each icon button (i.e., `<button><SVG></button>`) will have both
the button's aria-label read out as well as the title from the
SVG (which is usually just "image").

Since we are pretty good about setting aria-labels, we should instead
use `aria-hidden="true"` on these images, since they are not useful
to be read out.

I don't consider this a comprehensive review of all icons in the app,
but I knocked out all the low hanging fruit in this commit.

client/src/components/Prompts/BackToChat.tsx

@@ -19,7 +19,7 @@ export default function BackToChat({ className }: { className?: string }) {
       href="/"
       onClick={clickHandler}
     >
-      <ArrowLeft className="icon-xs mr-2" />
+      <ArrowLeft className="icon-xs mr-2" aria-hidden="true" />
       {localize('com_ui_back_to_chat')}
     </a>
   );