feat(trace): add retry after header

[GALLLASMILAN]

Closes: #16

Changes

I added the Retry-After

Definition

The HTTP Retry-After response header indicates how long the user agent should wait before making a follow-up request. There are three main cases this header is used:

• In a 503 Service Unavailable response, this indicates how long the service is expected to be unavailable.
• In a 429 Too Many Requests response, this indicates how long to wait before making a new request.
• In a redirect response, such as 301 Moved Permanently, this indicates the minimum time that the user agent is asked to wait before issuing the redirected request.

for /v1/traces/{id} route

I added this header only for this one route, not for all 404 responses

A 404 Not Found status code signifies that the resource does not exist on the server. Since the issue is not temporary, retrying the request later usually won’t make sense. For clients, this may cause confusion, as Retry-After suggests that the resource might become available after some time, which is contradictory to the meaning of 404.

! Because in the case of v1/traces/{id} the resource is temporarily unavailable. !