fix: use custom start scripts instead of brittle patch files

[skaldarnar]

Okay, I've ended up going down the path suggested in #547 and adding custom templates based on the default start scripts provided by Gradle to this repo.

They contain a minimal addition to set JAVA_HOME local to the jre folder in APP_HOME. That way, the local JRE should be picked up when starting the launcher.

How to test

• gradlew install...Dist (with ... being Linux64, Windows64, or Mac) to build the distribution for Windows
• start the launcher via bin/TerasologyLauncher.bat or bin/TerasologyLauncher
• download a game and start it
• check logs that it is using the local Java

Resolves #547

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Original PR description:

The start scripts are generated by gradlew startScripts, and the patch logic hooks up to it via doLast. I've updated the patch files by adjusting the .orig files as required, and then running diff -u on it (from within build/scripts/).

After this update, I at least don't see any rejections .rej anymore.

[skaldarnar]

Although this "solves" #547 I don't want to close that issue, as it describes the fact that this patch-workaround is quite brittle and will like break again in the future :see_no_evil:

My comment over there still holds - I want to move the launcher to jlink/jpackage rather than maintaining a custom copy of the start scripts. If anybody who understands Gradle a bit better (@keturn :wink:) happens to find the time for a PR to add customized scripts that contribution is very welcome.

[jdrueckert]

Launcher Fixes & Improvements

[keturn]

A note about that avro dependency: The fork has updated its documentation at https://github.com/zolyfarkas/avro and there is a new repo available for those, hosted by GitHub Packages.

The disadvantage is that using a GitHub Packages repository requires setting the credentials in your build environment: https://docs.github.com/en/packages/working-with-a-github-packages-registry/working-with-the-gradle-registry