Add handler name http runtime

[filafb]

What is the purpose of this pull request?

This PR adds labels to the request handlers for the routes added by the node sdk to all applications -/healthcheck, /_metrics and /:account/:workspace/_whoami. Currently, the handler undefined is TOP 5 handler in the metrics for runtime_http_requests_total - ref:

one thing that doens't make sense to me is the scale in this dashboard - I might have queried it wrong, but the intention here is to show the relevance of the undefined events

What problem is this solving?

The handler name is added to the metrics based on ctx.requestHandlerName - ref. The requestHandlerName is added by the nameSpanOperation Middleware, and it's applied to the appHttpHandlers, appEventHandlers and appGraphQLHandlers not to the runtimeHttpHandlers - here.

• For the appHttpHandlers, it's is applied for both private and public routes, it's added here and here;
• For the appEventHandlers, it's applied here;
• For the appGraphQLHandlers, it's applied here.

By adding the requestHandlerName to the context in the routes created by runtimeHttpHandlers we should be able to better filter the http metrics for applications.

[silvadenisaraujo]

LGTM 🔥