Update samples to use `semanticDescription` property

[Garry Trinder]

Update samples to use the new semanticDescription property

https://learn.microsoft.com/microsoftteams/platform/messaging-extensions/high-quality-message-extension?tabs=tasks#semantic-description

[Garry Trinder]

Closing as semantic description functionality has not yet been released to WW tenants.

[Martin Amm]

We are in the "Microsoft Copilot Developer Tenant Private Preview Program" - should it be available there?