Move Mesh Rule Router to SPI Extensions

[heliang666s]

What is the purpose of the change

Move Mesh Rule Router to SPI Extensions

Brief changelog

remove relative files

Verifying this change

No

Checklist

• [x] Make sure there is a GitHub_issue field for the change (usually before you start working on it). Trivial changes like typos do not require a GitHub issue. Your pull request should address just this issue, without pulling in other changes - one PR resolves one issue.
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• [ ] Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
• [ ] Check if is necessary to patch to Dubbo 3 if you are work on Dubbo 2.7
• [ ] Write necessary unit-test to verify your logic correction, more mock a little better when cross module dependency exist. If the new feature or significant change is committed, please remember to add sample in dubbo samples project.
• [ ] Add some description to dubbo-website project if you are requesting to add a feature.
• [ ] GitHub Actions works fine on your own branch.
• [ ] If this contribution is large, please follow the Software Donation Guide.