integration test for fully initialization

[xuan-cao-swi]

Description

(AI-generated test case)

This test case simulates the complete workflow of the apm-ruby agent, from initialization through sending a simple HTTP request.

Rather than initializing through the standard require 'solarwinds_apm', it mimics the initialization process defined in otel_config (such as OpenTelemetry::SDK.configure).

1. SWO components are added after OpenTelemetry initialization, mirroring the otel_config initialization step.
2. The HTTP request executes the OTLP processor and Oboe sampler logic, simulating real-world interactions.
3. Finally, the test case asserts span attributes and metrics to verify the expected results.

Test (if applicable)