Add TracyIsStarted

When using TRACY_MANUAL_LIFETIME, calling most Tracy functions
before starting the profiler results in an assertion. Notably, even
TracyIsConnected is affected. There is, however, no function to check if
the profiler had already started. This commit adds such a function.

public/client/TracyProfiler.hpp

@@ -51,6 +51,10 @@ namespace tracy
 #if defined(TRACY_DELAYED_INIT) && defined(TRACY_MANUAL_LIFETIME)
 TRACY_API void StartupProfiler();
 TRACY_API void ShutdownProfiler();
+TRACY_API bool IsProfilerStarted();
+#  define TracyIsStarted tracy::IsProfilerStarted()
+#else
+#  define TracyIsStarted true
 #endif
 
 class GpuCtx;