feat: Platform-specific distribution packages

[skaldarnar]

Clean up and improve packaging for Windows and Linux.

Addressing #492

To test you can run:

./gradlew install<distributionName>Dist

to install the distribution to build/install/<distributionName>, e.g., ./gradlew installLinux64Dist.

Packaging for all platforms can be tested via ./gradlew createRelease.

[jdrueckert]

Works fine for windows.
According to @praj-foss the .desktop would need to be copied to ~/.local/share/applications/.
We don't have a hard requirement for the .desktop file and it's easier to set this up with an installer script (which is one of our 4.x targets). So, let's only put the launcher start binary/script at the archive top-level and delay the .desktop file to after the v4.0 release.

[jdrueckert]

whitespaces

[jdrueckert]

Works well for 64-bit Linux 👍
For 32-bit Linux I get the following error:

Exception in thread "main" java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767)
Caused by: java.lang.UnsupportedOperationException: Internal Error
	at com.sun.glass.ui.gtk.GtkApplication.lambda$new$5(GtkApplication.java:158)
	at java.security.AccessController.doPrivileged(Native Method)
	at com.sun.glass.ui.gtk.GtkApplication.<init>(GtkApplication.java:140)
	at com.sun.glass.ui.gtk.GtkPlatformFactory.createApplication(GtkPlatformFactory.java:41)
	at com.sun.glass.ui.Application.run(Application.java:146)
	at com.sun.javafx.tk.quantum.QuantumToolkit.startup(QuantumToolkit.java:257)
	at com.sun.javafx.application.PlatformImpl.startup(PlatformImpl.java:211)
	at com.sun.javafx.application.LauncherImpl.startToolkit(LauncherImpl.java:675)
	at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:337)
	at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:328)
	... 5 more

Could well be, though, that that's a flaw in my setup. @praj-foss could you double-check whether 32-bit works on your linux?

[praj-foss]

I tested both Linux32 and Linux64 installs, and both seem to start alright. 👍
Verified the log file contents too. 👍

Linux32: OS: Linux i386 5.5.9-zen1-2-zen
Linux64: OS: Linux amd64 5.5.9-zen1-2-zen

[jdrueckert]

Successfully tested for 32- and 64-bit Windows 👍