Be more selective when prevent the click event on a solution or hin…

…t accordion.

Only prevent the default click behavior when the user clicks on the
summary or something within the summar. Allow the click event default to
occur otherwise.

This fixes issue openwebwork#1178.

htdocs/js/Problem/details-accordion.js

@@ -8,7 +8,9 @@
 		const collapse = new bootstrap.Collapse(collapseEl, { toggle: false });
 		button.addEventListener('click', () => collapse.toggle());
 
-		details.addEventListener('click', (e) => e.preventDefault());
+		details.addEventListener('click', (e) => {
+			if (button.contains(e.target)) e.preventDefault();
+		});
 		collapseEl.addEventListener('show.bs.collapse', () => {
 			details.open = true;
 			button.classList.remove('collapsed');