Add SetThreadUILanguage, SetThreadPreferredUILanguages and GetThreadUILanguage in c.s.j.p.win32.Kernel32

[overpathz]

Hi.

The SetThreadUILanguage function sets the user interface language for the current thread, which can be useful in situations where you need to ensure consistent language settings across an application. In my project, we are currently calling this function from C++ before starting the Java application, which adds overhead and creates inconsistency.

By adding the SetThreadUILanguage function to Kernel32, you can call it directly from Java code, which would streamline your application's startup process and ensure that language settings are consistent throughout the application. This would eliminate the need to call the function from C++ and would make the code easier to maintain and update.

[matthiasblaesing]

In general looks good to me. I left a few inline comments.

[overpathz]

Thanks for the review, supposedly everything has been fixed.

[matthiasblaesing]

@overpathz thank you for the updates. I pushed the PR to appveyor and got a test failure on x86 (32bit JDK):

https://ci.appveyor.com/project/matthiasblaesing/jna/builds/46657755/job/vf95hkhb08ax9cyx#L2772

The second thing I'd like to ask is whether it is possible to test setThreadPreferredUILanguages with multiple values. You test it with an empty array, which is more than other bindings in the codebase can say, but it would be good. Alternatively, is there a way how I can test it manually?

[overpathz]

Yes, thanks, I looked at the test. But unfortunately, at the moment I cannot continue the investigate/implementation due to the fact that the machine with Windows has broken, now only mac.

Therefore, the contribution continues when a new laptop is purchased.

Thanks for understanding.