Server spans should use templated route/url as the span name

[owais]

From Otel spec:

In case of HTTP servers, these endpoints are often mapped by the server frameworks to more concise HTTP routes, e.g. /api/users/{user_id}, which are recommended as the low cardinality span names.

https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/semantic_conventions/http.md#name

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All server instrumentations should be updated to confirm with the spec.

• URL/Route templates should be used as the span name.
• When it is not possible retrieve the templated URL/route, instrumentations should fall-back on the view/controller/function name. For example, UserHandler.get where UserHandler is a Python class and get is the method that served the HTTP request.
• Finally if none of the above are possible, instrumentations should fall back on HTTP {method}. For example, HTTP GET for GET requests and so on.