[Resilience] Allow changing the severity of standard resilience handlers

Polly allows us to configure telemetry of a pipeline.

```
httpClientBuilder
.AddResilienceHandler("something", (builder, context) =>
{
var telemetryOptions = new TelemetryOptions(context.GetOptions())
{
SeverityProvider = ev => ResilienceEventSeverity.Debug,
};

builder.ConfigureTelemetry(telemetryOptions);
});
```

Is it possible to add something like this to `AddStandardResilienceHandler` ?

```
httpClientBuilder.AddStandardResilienceHandler(x =>
{
x.Retry.MaxRetryAttempts = 5;
x.CircuitBreaker.SamplingDuration = TimeSpan.FromMinutes(TimeInMinutes * 2);
x.AttemptTimeout.Timeout = TimeSpan.FromMinutes(TimeInMinutes);
x.TotalRequestTimeout.Timeout = TimeSpan.FromMinutes(TimeInMinutes * x.Retry.MaxRetryAttempts);
});
```