Fix: Optimized variable node display and Agent template multi-language support #3221 (#9787)

### What problem does this PR solve?

Fix: Optimized variable node display and Agent template multi-language
support #3221

- Modified the VariableNode component to add parent label and icon
properties
- Updated the VariablePickerMenuPlugin to support displaying parent
labels and icons
- Adjusted useBuildNodeOutputOptions and useBuildBeginVariableOptions to
pass new properties
- Optimized the Agent TemplateCard component to switch the title and
description based on the language

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

web/src/pages/agent/operator-icon.tsx

@@ -64,7 +64,12 @@ const OperatorIcon = ({ name, className }: IProps) => {
 
   if (name === Operator.Begin) {
     return (
-      <div className="inline-block p-1 bg-accent-primary rounded-sm">
+      <div
+        className={cn(
+          'inline-block p-1 bg-accent-primary rounded-sm',
+          className,
+        )}
+      >
         <HousePlus className="rounded size-3" />
       </div>
     );