automation, rearrange folder

[XiaofeiCao]

Description

• fix [FEATURE REQ] eng, move SDK automation out of eng/mgmt folder #38985
  • old folder structure:
    • eng
      • mgmt
        • automation
          • script files
        • changelog
          • changelog tool files
  • new folder structure:
    • eng
      • automation
        • changelog
          • changelog tool files
        • script files
• Tests
  • codegen
    • generate.yml
      • TypeSpec: https://dev.azure.com/azure-sdk/internal/_build/results?buildId=3948535&view=results
      • Swagger: https://dev.azure.com/azure-sdk/internal/_build/results?buildId=3948536&view=results
    • generate_data.yml related pipeline seems disabled, not tested: https://dev.azure.com/azure-sdk/internal/_build?definitionId=3590
  • sdk automation(test-repo-billy)
    • config change: https://github.com/test-repo-billy/azure-rest-api-specs/blob/main/specificationRepositoryConfiguration.json#L15
    • mgmt TypeSpec: sdkautomation breaking change, mgmt typespec test-repo-billy/azure-rest-api-specs#3381
    • mgmt Swagger: mgmt swagger test-repo-billy/azure-rest-api-specs#3382
    • dpg TypeSpec: dpg typespec test-repo-billy/azure-rest-api-specs#3383
• related PRs
  • java update automation config azure-rest-api-specs#29777
  • fix api-specs.yml location weidongxu-microsoft/release-automation-devops#11
• future work
  • fix generate.yml pipeline yaml file location

Please add an informative description that covers that changes made by the pull request and link all relevant issues.

If an SDK is being regenerated based on a new swagger spec, a link to the pull request containing these swagger spec changes has been included above.

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