Ensure C compatibility for guest tracing

## Description
We want Hyperlight guest tracing to be compatible with C guests.
We haven't tried it, but using a C guest should at least allow the `hyperlight` guest framework traces to be reported to the host.

## Rationale
All type of Hyperlight guests shall have support for guest tracing.

## How
We need tests to ensure this compatibility.
Furthermore, to allow a guest to add custom traces in its code, we need to provide some macros/APIs that do that for the C guests. Or find a way to exercise the `tracing` subscriber's APIs.