.Net: Exception handling consistency for FunctionCallContent class.

[SergeyMenshykh]

Motivation and Context

The FunctionCallContent.InvokeAsync method throws exceptions in two cases: if the function invocation fails or the function is not found. However, it does not throw exceptions captured in the Exception property that might occur while mapping the function call represented by the AI connector-specific function call model to the connector-agnostic FunctionCallContent model class.

This introduces inconsistency in the way exceptions are handled by the FunctionCallContent.InvokeAsync method and may lead to intermittent failures in the calling code that are difficult to troubleshoot and identify the root cause of.

Description

This PR throws the function call mapping exception captured by the Exception property.

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the SK Contribution Guidelines and the pre-submission formatting script raises no violations
• All unit tests pass, and I have added new tests where possible
• I didn't break anyone 😄

[RogerBarreto]

This might have a big consequence for all, as much of the failing scenarios were silent before and now may throw on the caller code.