fix: report partial consumer group batch deletion outcomes

[Aias00]

Summary

• continue deleting selected consumer groups after an individual deletion fails
• return deleted and failed outcomes from the service layer
• remove only successful rows and keep failed rows selected for retry

Closes #1084

Verification

• npm test -- --run src/services/consumerService.batchDelete.test.ts src/pages/instance/__tests__/ConsumerPage.test.tsx
• npm run lint
• npm run build

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[RockteMQ-AI]

LGTM. Good improvement — batch deletion now continues after individual failures and reports exact outcomes (deleted/failed). Failed groups stay selected for easy retry, and the warning message clearly shows partial success. Service layer test and UI integration test both cover the partial-failure scenario thoroughly.

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Automated review by github-manager-bot

[lizhimins]

Closing: already covered by the consolidated UI fix PR #1234 (merged as 2fa5d78, which integrated #1170's partial batch-delete outcomes with the instance-scoped signature). Thanks for the contribution! / 关闭说明：批量删除部分失败透出已由 #1234（合入 SHA 2fa5d78，整合 #1170 并与 instance 作用域签名合并）覆盖。感谢贡献！