Compiler update to Delphi 12.1

All upcoming HeidiSQL builds and releases will use the latest Delphi 12.1 compiler from Embarcadero. This should definitely raise quality, probably even fix some bugs.

If you like to compile HeidiSQL yourself, or probably start your own project using Delphi, you can get a trial of Delphi for free: https://www.embarcadero.com/products/delphi/start-for-free