Application Insights dependency telemetry not working.

[stebet]

Filing this as an issue, but it doesn't seem to be fixable until a new version of the Azure Functions Worker SDK is released. See these issues for details:

• Azure/azure-functions-dotnet-worker#308
• Azure/azure-functions-dotnet-worker#439

This seems to be broken for .NET 5.0 functions running in isolation mode.

Tagging @fabiocav and @brettsam for visibility as well.

[stebet]

This might get fixed by #33. Will do some testing to see if that resolves the issues.