[python] Fix XML deserialization for enum/datetime types and add mock API tests#3347

msyyc merged 5 commits intomainAzure/autorest.python:mainfrom

auto-microsoft-copilot/add-test-case-for-pull-9660Azure/autorest.python:auto-microsoft-copilot/add-test-case-for-pull-9660Copy head branch name to clipboard