[REQ][CSHARP][GENERICHOST] Replace deprecated Microsoft.Extensions.Http.Polly dependency

[alec-petersen]

Is your feature request related to a problem? Please describe.

Microsoft announced that Microsoft.Extensions.Http.Polly is deprecated.

Describe the solution you'd like

We should adopt one of the supported packages instead (Microsoft.Extensions.Resilience and Microsoft.Extensions.Http.Resilience). I have not looked into the exact work to do this quite yet, but I am happy to work on this. I think we'll need to keep the polly dependency around for people generating on .net versions older than .NET 6 but we'll see.

[alexaka1]

+1 as Polly v7 is also deprecated, and Polly.Core is the favoured package to use. If both pulled it causes ambiguity on lot of references.