fix(ai-help): hide "Stop answering" before we respond (#10530)

* fix(ai-help): hide "Stop answering" before we respond

* chore(ai-help): hide all disabled footer actions

Author: caugner

Diff for: client/src/plus/ai-help/index.scss

@@ -187,6 +187,10 @@
 
       .ai-help-footer-actions {
         padding-bottom: 0.5rem;
+
+        button:disabled {
+          visibility: hidden;
+        }
       }
 
       .ai-help-footer-text {

Diff for: client/src/plus/ai-help/index.tsx

@@ -698,6 +698,7 @@ export function AIHelpInner() {
                 <div className="ai-help-footer-actions">
                   <Button
                     type="action"
+                    isDisabled={!isResponding}
                     extraClasses="ai-help-stop-button"
                     onClickHandler={() => {
                       gleanClick(`${AI_HELP}: stop`);