Skip adding messages to context when invocation fails with exception

[Copilot]

Motivation and Context

Addresses review feedback from #2505: #2505 (comment)

The ContextualFunctionProvider was adding failed invocation messages to its context history, polluting the conversation state with messages from unsuccessful operations.

Description

Modified InvokedAsync to check context.InvokeException and use an early return pattern when invocations fail:

public override ValueTask InvokedAsync(InvokedContext context, CancellationToken cancellationToken = default)
{
    Throw.IfNull(context);

    // Don't add messages to the recent messages queue if the invocation failed
    if (context.InvokeException is not null)
    {
        return default;
    }

    // Add the request and response messages...
    
    return default;
}

Implementation Details

• Uses early return pattern to check for exceptions before processing messages
• Skips adding request and response messages to the recent messages queue when InvokeException is not null
• Maintains cleaner code structure with reduced nesting

Test Coverage

• Added InvokedAsync_ShouldNotAddMessages_WhenExceptionIsPresent_Async to verify messages from failed invocations are excluded from context history

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the Contribution Guidelines
• All unit tests pass, and I have added new tests where possible
• Is this a breaking change? If yes, add "[BREAKING]" prefix to the title of the PR.

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[westey-m]

@copilot Instead of having an if around all the code, just have an if that checks if InvokeException is not null and return if so.

[Copilot]

Refactored to use early return pattern in commit 70b0e76.

[westey-m]

Please fix requested item

[Copilot]

Please fix requested item

Could you clarify what needs to be fixed? The early return pattern was implemented in commit 70b0e76 as requested. The current code checks if context.InvokeException is not null and returns early before adding any messages to the queue.