Refactor: Move backend files to backend/ directory and split .gitignore

backend/src/ea_chatbot/utils/__init__.py

@@ -0,0 +1,12 @@
+from .db_client import DBClient
+from .llm_factory import get_llm_model
+from .logging import get_logger, LangChainLoggingHandler
+from . import helpers
+
+__all__ = [
+  "DBClient",
+  "get_llm_model",
+  "get_logger",
+  "LangChainLoggingHandler",
+  "helpers"
+]