Java path for kotlin tests compilation on Windows machines

[SergeyDatskiv]

In this merge request we are closing an issue where Windows users who did not have java in their PATH variable could not run the generated kotlin tests because kotlinc requires Java to be in the path variable.

Description of changes made

To address this issue, I added the same Java Path, which is used by the JavaTestCompiler to the KotlinTestCompiler class. This required changing the TestCompilerFacotry to find the Java path and pass it to KotlinTestCompiler. I decided to remove dedicated functions for creating Kotlin and Java test compilers because I thought that now they are more similar than different. Instead, I added a private function for finding the Java home path.

The KotlinTestCompiler now gets a javaHomeDirectoryPath which is not directly assigned in the constructor because that would require changing the TestCompiler class. I thought that TestCompiler class should not be dedicated to the Java / Kotlin language, hence I did not change it.

The Java path is set only if we detect that the system is a Windows machine. It is set through a chain of commands via command prompt.

Other notes

• Please test that nothing broke on Mac with regard to Java- and Kotlin-based test case generation. Thanks!

Why is merge request needed

Closes #410

• I have checked that I am merging into correct branch

[Hello-zoka]

Probably closes #320

[Vladislav0Art]

Kotlin compilation modulo this issue works on my Windows now.

[Vladislav0Art]

Approved with minor suggestions. There is a question about the Java home path param in the Kotlin compiler.

I checked both Java and Kotlin test generation on Mac. Both work as expected.