templates: Add neo4j semantic layer with ollama template (#17192)

A template with JSON-based agent using Mixtral via Ollama.

---------

Co-authored-by: Erick Friis <erick@langchain.dev>

templates/neo4j-semantic-ollama/main.py

@@ -0,0 +1,17 @@
+from neo4j_semantic_ollama import agent_executor
+
+if __name__ == "__main__":
+    original_query = "What do you know about person John?"
+    followup_query = "John Travolta"
+    chat_history = [
+        (
+            "What do you know about person John?",
+            "I found multiple people named John. Could you please specify "
+            "which one you are interested in? Here are some options:"
+            "\n\n1. John Travolta\n2. John McDonough",
+        )
+    ]
+    print(agent_executor.invoke({"input": original_query}))
+    print(
+        agent_executor.invoke({"input": followup_query, "chat_history": chat_history})
+    )