Fix Otel Support: use agent sdk when there is one

[ahmedmuhsin]

This pull request introduces several improvements and refactorings to the OpenTelemetry integration for Azure Functions in Java. The main focus is on making the SDK initialization more robust and agent-agnostic, improving resource detection documentation and logic, and updating test dependencies and build plugins for better compatibility and reliability.

SDK Initialization and Robustness

• Refactored FunctionsOpenTelemetry to support agent-agnostic initialization, caching the global OpenTelemetry instance, and ensuring thread-safe, idempotent setup. Initialization now works seamlessly with or without an OpenTelemetry agent, and avoids unnecessary global registration. [1] [2]
• Improved error handling and shutdown logic during SDK setup, and switched to using buildAndRegisterGlobal for fallback scenarios.

Resource Detection Documentation and Logic

• Expanded and clarified Javadoc comments in FunctionsResourceDetector to document the resource detection process, its modes (local vs. Azure-hosted), and the mapping to OpenTelemetry semantic conventions. Attribute and environment variable documentation was made more explicit.
• Improved code comments and variable naming in resource detection logic for clarity, including construction of ARM resource IDs and deployment environment attributes. [1] [2] [3] [4]

API Usability and Convenience

• Added new convenience methods and validation helpers for span creation in FunctionsOpenTelemetry, including a default tracer name and overloads for trace context usage.

Build and Test Dependency Updates

• Updated the project version to 1.1.0 and downgraded junit.jupiter.version to 5.9.3 for compatibility. [1] [2]
• Added junit-jupiter-engine and junit-platform-launcher test dependencies, and introduced the maven-surefire-plugin for improved test execution. [1] [2]

[swapnil-nagar]

Curious, why we need initialized parameter fir thread safety, why can't globelOtel can be used.

Concern I have is there are two volatile variables to support same functionality.

`public static void initialize() {
if (globelOtel!= null) {
return; // Fast path
}

    synchronized (FunctionsOpenTelemetry.class) {
        if (globelOtel!= null) {
            return; // Double-check after acquiring lock
        }

        io.opentelemetry.api.OpenTelemetry global = GlobalOpenTelemetry.get();

        if (isNoOp(global)) {
            LOGGER.info("No global OpenTelemetry found; initializing SDK.");
            globelOtel= buildSdk(); 
        } else {
            LOGGER.info("GlobalOpenTelemetry already set; using existing instance.");
            globelOtel= global;
        }
    }
}

`

[swapnil-nagar]

if (globelOtel!= null)

[swapnil-nagar]

What is the order()?