Disable DiagnosticSource and HttpClient integrations where this would duplicate OTel instrumentation

[jamescrosswell]

Description

For the HttpClient integration we might need a way to control breadcrumbs, failed requests and tracing separately.

[linear]

NET-484

[Flash0ver]

Another observation we made is that the flag
options.DisableSentryHttpMessageHandler = true;
is different from other "Disable-Integration" options which are methods rather than a property.

Is this by design or accidental?

I can imagine the difference is that it's not a ISdkIntegration.

[jamescrosswell]

I think this is covered off by #4899:

• feat: Add support to send OTEL traces via OTLP #4899

For the POTEL integration, we've added some comments to the public extension methods to encourage people to do this and to let them know we'll be deprecating that integration eventually.

Closing this for now then.