[v2.0] Refactor Microsoft Teams Get*Settings to use typed struct

Goal

Implement a typed struct for Microsoft Teams integration settings.

Instructions

1. Investigation: Perform an API GET to identify the specific property keys returned for this integration.
2. Struct Definition: Define MicrosoftTeamsIntegration and MicrosoftTeamsIntegrationProperties based on investigation results.
3. Refactor: Update GetProjectMicrosoftTeamsSettings and GetGroupMicrosoftTeamsSettings.
4. Validation: Run make generate and ensure all tests pass.

Parent Epic: #2198 /label ~"Hackathon::FY26-Q4" ~"breaking change" ~"client-go::2.0"