CLI meets output breaking when migrate to new SDK generated from Typespec

[msyyc]

CLI output with old SDK:

CLI output with new SDK:

[msyyc]

Root cause is that CLI has special serialization logic https://github.com/Azure/azure-cli/blob/3b51ff5a6ee14b1cf6414bc6efbefcbce7342941/src/azure-cli-core/azure/cli/core/util.py#L659-L667 which outputs flattened output before.