feat(logging): add a logging middleware to log all api requests

[lsampras]

Type of Change

• Bugfix
• New feature
• Enhancement
• Refactoring
• Dependency updates
• Documentation
• CI/CD

Description

• Create a request middleware to create a top level span consisting of all the metadata fields
• Update the subscriber layer to propogate the metadata fields to the top layer

Additional Changes

• This PR modifies the API contract
• This PR modifies the database schema
• This PR modifies application configuration/environment variables

Motivation and Context

• Currently we don't have guaranteed keys/metadata present at the top level
• finding the relavant info (payment_id/connector etc) requires context about the lower level functions where this info is extracted
• instead this change provides a single log line that is guaranteed to be present for all API calls
• And this log line would have all the relevant fields needed for analysis/debugging

How did you test it?

run the application locally
all api requests should have the following log line at the end of request

• the fields should be populated when available
• These log line will be generated even for health & non-existent paths (e.g / or /favicon.ico)

{
    "message": "[GOLDEN_LOG_LINE - EVENT] REQUEST MIDDLEWARE END",
    "hostname": "<MY_MACHINE>.local",
    "pid": 62901,
    "env": "development",
    "level": "INFO",
    "target": "router::middleware",
    "service": "router",
    "line": 61,
    "file": "crates/router/src/middleware.rs",
    "fn": "golden_log_line",
    "full_name": "router::middleware::golden_log_line",
    "time": "2024-01-24T06:35:06.771569000Z",
    "merchant_id": "merchant_1706060159",
    "request_id": "018d3a2d-e583-7581-8992-8596b3052995",
    "extra": {
        "trace_id": "00000000000000000000000000000000",
        "http.method": "POST",
        "http.route": "/payments",
        "http.flavor": "1.1",
        "http.user_agent": "PostmanRuntime/7.33.0",
        "payment_id": "payment_intent_id = \"pay_y8XHx5whOaWTdoGrgAAf\"",
        "otel.name": "HTTP POST /payments",
        "http.client_ip": "::1",
        "http.host": "localhost:8080",
        "http.target": "/payments",
        "http.scheme": "http",
        "otel.kind": "server"
    }
}

Checklist

• I formatted the code cargo +nightly fmt --all
• I addressed lints thrown by cargo clippy
• I reviewed the submitted code
• I added unit tests for my changes where possible
• I added a CHANGELOG entry if applicable