Add AddHttpClientInstrumentation and DisableSentryHttpMessageHandler to OTEL docs

[jamescrosswell]

We should add some detail here:
https://docs.sentry.io/platforms/dotnet/guides/aspnetcore/tracing/instrumentation/opentelemetry/

Lots of people get tripped up when adding OTEL and not removing Sentry instrumentatioin.

Originally posted by @jason-kingsmill in #4655

[linear]

NET-510

[ericsampson]

Wouldn't it be a better user experience that UseOpenTelemetry() automatically did the equivalent of setting DisableSentryHttpMessageHandler = true ?

Having said that, the HttpMessageHandler settings should have the ability to decouple "does it send traces" and "does it captured failed requests as Issues"

[jamescrosswell]

Wouldn't it be a better user experience that UseOpenTelemetry() automatically did the equivalent of setting DisableSentryHttpMessageHandler = true ?

I think that would be a good default yes

Having said that, the HttpMessageHandler settings should have the ability to decouple "does it send traces" and "does it captured failed requests as Issues"

Yeah that should be covered here:

• Allow disabling just tracing on HTTP client requests #4695