[Feature] Dubbo MCP In Multiple Instances Proposal

### Pre-check

- [x] I am sure that all the content I provide is in English.

### Search before asking

- [x] I had searched in the [issues](https://github.com/apache/dubbo/issues?q=is%3Aissue) and found no similar feature requirement.

### Apache Dubbo Component

Java SDK (apache/dubbo)

### Descriptions

Currently, #15406 lacks a solution for multiple instances of MCP Server, which involves session sharing issues in cluster mode. However, the multi-instance solution is an enterprise-level solution, which can be implemented after this PR is merged

### Related issues

#15332

### Are you willing to submit a pull request to fix on your own?

- [ ] Yes I am willing to submit a pull request on my own!

### Code of Conduct

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