Add GDScript stack trace in capture_message/event

The idea is to add a GDScript stack trace automatically whenever user code calls `SentrySDK.capture_message()` or `SentrySDK.capture_event()` from GDScript. For instance, on Android, auto-instrumentation adds a Java stack trace; however, it isn’t particularly helpful for Godot development. We could also add an option to opt-out from such feature.
