[Feature] Dynamic load MCP tools and prompts in runtime.

### Search before asking

- [x] I searched in the [issues](https://github.com/apache/flink-agents/issues) and found nothing similar.

### Description

Currently, we load tools and prompts provided by MCP server during the compile time, which requires connecting remote MCP server in compilation.
We anticipate the need to support dynamic loading and unloading of tools, and the MCP Server may also dynamically update prompts or tools. In this case, statically obtaining the list of prompts and tools at compile time has limitations.

### Are you willing to submit a PR?

- [ ] I'm willing to submit a PR!

Start by tracing how tools and prompts from MCP servers are obtained during compilation, then identify the runtime entry points involved. Done means tools and prompts can be loaded and unloaded dynamically, and updates from the MCP server can be reflected without requiring compilation.

Written by the indexing model from the issue text.