Enable FastMCP to filter tools, prompts, resources using a fine grained policy

Description

The authorization protocol allows MCP to implement course grained authorization checks e.g. a principal can/cannot access the server.

For advanced use cases though it is useful to be able to limit access on a per tool/resource/prompt basis.

There are a range of authorization tools that can be used however rather than being specific I suggest it is better to provide a plugin API that allows providers to pick their underlying authorization approach.

I have a patch that shows this idea, I'll open a draft pull request to illustrate the idea and allow for further testing & refinement.

References

No response

首先審查細粒度授權提案以及 issue 中提到的修補程式，然後將其與 MCP 授權協定進行比較。當 FastMCP 提供一個 provider plugin API，能夠分別獨立地允許或拒絕對工具、提示和資源的存取，並透過測試完善此方法時，工作就完成了。