Add `RequestTelemetry.TryGetRequestBody`, `RequestTelemetry.TryGetResponseBody`, `DependencyTelemetry.TryGetRequestBody` and `DependencyTelemetry.TryGetResponseBody`

[OskarKlintrot]

Is your feature request related to a problem? It's a bit cumbersome to read and add the request/response body to the RequestTelemetry.Properties (and DependencyTelemetry.Properties).

Describe the solution you'd like. Similar to how a lot of objects are avalible for the end user in DependencyTelemetry.TryGetOperationDetail(String, Object) it would be very helpful to also be able to be able to access the request/response body in a similar fashion.

Describe alternatives you've considered. Doing it "manually" works, but would be nice to only having to handle the privacy-part of the issue.

Additional context.

Need to evaluate if similar concept can be extended to Requesttelemetry as well. We have quite large number of customers asking for mechanism to read request/response body. While it can't be done by SDK by default (privacy etc.), if we populate the request/response objects in this way, users can access it in initializer and add to telemetry as desired. @cijothomas in a comment

[github-actions[bot]]

This issue is stale because it has been open 300 days with no activity. Remove stale label or this will be closed in 7 days. Commenting will instruct the bot to automatically remove the label.

[OskarKlintrot]

Not stale