Python: Fix broken samples and add missing READMEs (#5038)

* Python: Fix broken samples and add missing READMEs

- simple_context_provider: move instructions kwarg into options dict
- suspend_resume_session: use OpenAIChatCompletionClient for in-memory demo
- foundry_chat_client_with_hosted_mcp: move store kwarg into options dict
- Add README.md for context_providers and conversations sample folders

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Python: Fix additional sample issues in context_providers

- mem0_basic: send preferences query before sleep so Mem0 can learn them,
  print result from new session recall
- mem0_sessions: add session for multi-turn conversation in agent-scoped
  example, remove user_id from agent-scoped provider (Mem0 API stores
  memories without user_id when agent_id is provided), use single message
  for storing preferences
- redis_basics: print retrieved context messages instead of raw object
- redis_sessions: add missing load_dotenv() call
- redis_basics/redis_sessions: fix docstrings referencing wrong client type
- azure_redis_conversation: replace duplicate copyright with load_dotenv()

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Python: Fix broken link in declarative README

openai_responses_agent.py was renamed to openai_agent.py

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

python/samples/02-agents/declarative/README.md

@@ -68,7 +68,7 @@ Illustrates a basic agent using Azure OpenAI with structured responses.
 
 **Key concepts**: Azure OpenAI integration, credential management, structured outputs
 
-### 5. **OpenAI Responses Agent** ([`openai_responses_agent.py`](./openai_responses_agent.py))
+### 5. **OpenAI Responses Agent** ([`openai_agent.py`](./openai_agent.py))
 
 Demonstrates the simplest possible agent using OpenAI directly.