[FEATURE REQ] Support traffic routing for Azure web app

**Is your feature request related to a problem? Please describe.**
Azure CLI has a [feature](https://docs.microsoft.com/en-us/cli/azure/webapp/traffic-routing?view=azure-cli-latest) to mange traffic routing for web apps, the related java sdk does not support this feature yet.

**Describe the solution you'd like**
Add new interfaces for this feature gap.

**Describe alternatives you've considered**
None.

**Additional context**
None.

**Information Checklist**
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- [X] Expected solution specified