Qt6

Changelog

• Negative margins
• Qt6
• Updated Polish translation
• fix for openGL (wayland)

Additionally: Mod epbd

• epbd - added new threshold methods: EdgePlus and BlurDiv (ScanTailor-Advanced#48, ScanTailor-Advanced#47).
• qt5_win64_epdb - build by @plzombie (download vc runtime here).

Additionally: Mod epbdta

• epbdta - added thresholdAdjustment for all threshold (ScanTailor-Advanced#48, ScanTailor-Advanced#59).
• qt5_win64_epdbta - build by @plzombie (download vc runtime here).

Additionally: Mod epbdtaed

• epbdtaed - added new threshold method: EdgeDiv (EdgePlus & BlurDiv) (ScanTailor-Advanced#48, ScanTailor-Advanced#8).