[Feature](sql) Support filtering backends by ID in SHOW BACKENDS command

[heguanhui]

What problem does this PR solve?

Currently, the SHOW BACKENDS command can only display information about all backend nodes and cannot filter based on specific backend IDs. When a cluster has a large number of backend nodes, it's difficult for users to quickly locate the status information of specific backends.
This feature solves the following problems:

Operational Efficiency: Administrators can quickly view the status of specific backend nodes without manually searching through all backends
Monitoring Integration: Facilitates monitoring systems to query the status of specific backends
Troubleshooting: When a backend has issues, you can quickly get detailed information about that backend

Problem Summary:

Feature Description
Enhances the SHOW BACKENDS command to support filtering backend nodes by ID, including both single ID and multiple IDs (comma-separated) filtering methods.

• Test

  • Regression test
  • Unit Test
  • Manual test (add detailed scripts or steps below)
  • No need to test or manual test. Explain why:
    • This is a refactor/code format and no logic has been changed.
    • Previous test can cover this change.
    • No code files have been changed.
    • Other reason
      测试报告.docx

• Behavior changed:

  • No.
  • Yes.

• Does this need documentation?

  • No.
  • Yes.

Check List (For Reviewer who merge this PR)

• Confirm the release note
• Confirm test cases
• Confirm document
• Add branch pick label

[hello-stephen]

Thank you for your contribution to Apache Doris.
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Please clearly describe your PR:

1. What problem was fixed (it's best to include specific error reporting information). How it was fixed.
2. Which behaviors were modified. What was the previous behavior, what is it now, why was it modified, and what possible impacts might there be.
3. What features were added. Why was this function added?
4. Which code was refactored and why was this part of the code refactored?
5. Which functions were optimized and what is the difference before and after the optimization?