Align HTTP status code as span data field http.response.status_code

[antonpirker]

Send HTTP status codes as an integer in a Span data field called http.response.status_code.

This will align us with OTel. Also see:

• https://develop.sentry.dev/sdk/performance/span-data-conventions/#http

Fixes #2099

[antonpirker]

A note:

The OTel docs for their semantic conventions [1] say that it is called http.response.status_code (this is what we implemented)

But the OTel Python SDK still uses http.status_code [2].

Anyhow, the Sentry Otel integrations uses the variables from the OTel Python SDK, so if an OTel span has http.status_code set it will be transformed into http.response.status_code in the Sentry span and everything is fine.

1: https://opentelemetry.io/docs/specs/otel/metrics/semantic_conventions/http-metrics/#http-server
2: https://github.com/open-telemetry/opentelemetry-python/blob/9706ed004ae3c35ab393fb48c3d71d0c40e8c62b/opentelemetry-semantic-conventions/src/opentelemetry/semconv/trace/__init__.py#L279

[sentrivana]

One typo, otherwise LGTM