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/components/next-markdown-content/index.tsx

@@ -235,7 +235,7 @@ function MarkdownContent({
             <HoverCardTrigger>
               <CircleAlert className="size-4 inline-block" />
             </HoverCardTrigger>
-            <HoverCardContent>
+            <HoverCardContent className="max-w-3xl">
               {renderPopoverContent(chunkIndex)}
             </HoverCardContent>
           </HoverCard>