Implement support of HiDPI splash screen loading on Linux.
The following methods from splashscreen_impl.h need to be implemented (see JDK-8043869):
char* SplashGetScaledImageName(const char*, const char*, float*);
Some useful steps:
- get scale factor from the system (may be GDK_SCALE)
- it should be decided, which name conventions should be used for high-resolution splash images.