[Bug] Cannot query versionDescriptor.version with azure devops invoke

**Describe the bug**
A clear and concise description of what the bug is.

According to
[az devops invoke](https://docs.microsoft.com/en-us/cli/azure/ext/azure-devops/devops?view=azure-cli-latest#ext-azure-devops-az-devops-invoke)
[Items - Get](https://docs.microsoft.com/en-us/rest/api/azure/devops/git/items/get?view=azure-devops-rest-6.0)

I tried to get a file from azure-devops git with specific version:

```bash
az devops invoke --area git --resource items --route-parameters project="PROJECT" repositoryId="REPO" --query-parameters path=README.md --api-version=5.1 --versionDescriptor.version="master" --media-type application/zip --out-file readme.zip
```

However, I got this error:

**az: error: unrecognized arguments: --versionDescriptor.version=master**

What should I do to fix this issue?

**To Reproduce**
Azure Cli Version:
Use az --version
Look for something like-
azure-cli (2.0.70)

Azure-Devops extension version:
Use az --version
Look for something like-
Extensions:
azure-devops (0.18.0)

Steps to reproduce the behavior:
1. login using az login
2. setup defaults..
3. Run command....
4. See error

**Expected behavior**
A clear and concise description of what you expected to happen.

**Screenshots**
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**Debug logs**
Add the output of the command running it with debug mode (--debug)

**Additional context**
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