fix: Stacktraces for Debug.LogError events

[bitsandfoxes]

Fixes #1608

This PR restores the functionality of capturing Debug.LogError and provides stacktraces in the resulting event.

Before

After

Implementation Details

In this PR, we split the logging integration into two components:

• UnityLogHandlerIntegration
• UnityApplicationLoggingIntegration

The UnityLogHandlerIntegration hooks into the actual log handler and intercepts all logs. This allows us to access the exception object directly in case of Debug.LogException, but comes with notable limitations:

• We must call string.Format for each log captured as a breadcrumb
• We lose access to the stacktrace string that was previously available through Application.OnMessageReceived

To address these limitations, we now implement both approaches:

1. Capturing exceptions via UnityLogHandlerIntegration
2. Creating breadcrumbs for logs via UnityApplicationLoggingIntegration
3. Capturing LogErrors via UnityApplicationLoggingIntegration

We create a synthetic exception that parses the stringified stacktrace during capture and generates an event from it.

Known Limitations

Currently, we cannot provide line numbers for these issues. The IL2CPPEventProcessor requires an actually thrown exception to retrieve the necessary images and instruction addresses. In the case of Debug.LogError, no such exception exists.

[vaind]

Personally I'd have preferred regex as that would have been easier to read to me. But AFAICT, the manual parsing seems correct

[bruno-garcia]

concerning that we catch all and don't have any indication of what went wrong. debug logging at least?