Add Merge UI to V2 (#4235)

# Description of Changes
Add UI for Merge into V2.

frontend/src/components/tooltips/useMergeTips.tsx

@@ -0,0 +1,19 @@
+import { useTranslation } from 'react-i18next';
+import { TooltipContent } from '../../types/tips';
+
+export const useMergeTips = (): TooltipContent => {
+  const { t } = useTranslation();
+
+  return {
+    tips: [
+      {
+        title: t('merge.removeDigitalSignature.tooltip.title', 'Remove Digital Signature'),
+        description: t('merge.removeDigitalSignature.tooltip.description', 'Digital signatures will be invalidated when merging files. Check this to remove them from the final merged PDF.')
+      },
+      {
+        title: t('merge.generateTableOfContents.tooltip.title', 'Generate Table of Contents'),
+        description: t('merge.generateTableOfContents.tooltip.description', 'Automatically creates a clickable table of contents in the merged PDF based on the original file names and page numbers.')
+      }
+    ]
+  };
+};