Make jre folder platform dependent

[chippmann]

This makes the jre folder platform dependent.

This makes it possible for a project to have multiple jre folder simultaneously on the file system. The module then automatically picks the correct one for the current platform.
The main advantage of this is that on a project with multiple people working on it, the embedded jre can be committed to the repository for each platform together with the built jar and a project member does not need to have java locally installed and JAVA_HOME set. Which is especially useful if one is working with non programmers.

Note: Breaking change. Needs special notes in release notes!

[piiertho]

I think we need to test in exports to be sure we don't break them.

[chippmann]

I tested linux editor and export templates. Could you test windows and mac? (I don't think testing on mobile is necessary but you can if you want to :-) )

[chippmann]

Tested the exports and editors for linux amd64 with the changes @CedNaru requested.
Will test on macos later today

@piiertho need a review again from you as these were quite significant changes again

[chippmann]

Tested editor and export on macOS as well.

If you @CedNaru or @piiertho could test on windows, that would be appreciated.

[chippmann]

Tested it on mac and windows as well in the meantime. Just graalvm is missing testing on those platforms

[piiertho]

I don't remember: did we test it on all platforms ?

[chippmann]

I did on all platforms except mobile and graalvm for windows and macos
Although it might be worth to test again after my last change even though i did not change much about the logic of the export

[chippmann]

After my last change i did test the exports on macos (as thats where I'm working on today)
I'm currently in the process of trying to add export tests to the ci/cd pipeline. But depending on how that goes, it might be faster to test locally again.

[piiertho]

I will test it on graalVM native-image for iOS.

[piiertho]

Tested on iOS