feat: Add contact merge form component (#10478)

Co-authored-by: Pranav <pranavrajs@gmail.com>

app/javascript/dashboard/i18n/locale/en/contact.json

@@ -442,6 +442,26 @@
       }
     },
     "SIDEBAR": {
+      "MERGE": {
+        "TITLE": "Merge contact",
+        "DESCRIPTION": "Combine two profiles into one, including all attributes and conversations. In case of conflict, the primary contact’s attributes will take precedence.",
+        "PRIMARY": "Primary contact",
+        "PRIMARY_HELP_LABEL": "To be saved",
+        "PRIMARY_REQUIRED_ERROR": "Please select a contact to merge with before proceeding",
+        "PARENT": "To be merged",
+        "PARENT_HELP_LABEL": "To be deleted",
+        "EMPTY_STATE": "No contacts found",
+        "PLACEHOLDER": "Search for primary contact",
+        "SEARCH_PLACEHOLDER": "Search for a contact",
+        "SEARCH_ERROR_MESSAGE": "Could not search for contacts. Please try again later.",
+        "SUCCESS_MESSAGE": "Contact merged successfully",
+        "ERROR_MESSAGE": "Could not merge contacts, try again!",
+        "IS_SEARCHING": "Searching...",
+        "BUTTONS": {
+          "CANCEL": "Cancel",
+          "CONFIRM": "Merge contact"
+        }
+      },
       "NOTES": {
         "PLACEHOLDER": "Add a note",
         "WROTE": "wrote",