[Improvement] Use SQLite for chat memory (#910)

Co-authored-by: Deven Patel <deven298@yahoo.com>

tests/memory/test_memory_messages.py

@@ -0,0 +1,37 @@
+from embedchain.memory.message import BaseMessage, ChatMessage
+
+
+def test_ec_base_message():
+    content = "Hello, how are you?"
+    creator = "human"
+    metadata = {"key": "value"}
+
+    message = BaseMessage(content=content, creator=creator, metadata=metadata)
+
+    assert message.content == content
+    assert message.creator == creator
+    assert message.metadata == metadata
+    assert message.type is None
+    assert message.is_lc_serializable() is True
+    assert str(message) == f"{creator}: {content}"
+
+
+def test_ec_base_chat_message():
+    human_message_content = "Hello, how are you?"
+    ai_message_content = "I'm fine, thank you!"
+    human_metadata = {"user": "John"}
+    ai_metadata = {"response_time": 0.5}
+
+    chat_message = ChatMessage()
+    chat_message.add_user_message(human_message_content, metadata=human_metadata)
+    chat_message.add_ai_message(ai_message_content, metadata=ai_metadata)
+
+    assert chat_message.human_message.content == human_message_content
+    assert chat_message.human_message.creator == "human"
+    assert chat_message.human_message.metadata == human_metadata
+
+    assert chat_message.ai_message.content == ai_message_content
+    assert chat_message.ai_message.creator == "ai"
+    assert chat_message.ai_message.metadata == ai_metadata
+
+    assert str(chat_message) == f"human: {human_message_content} | ai: {ai_message_content}"