Defer TEMP_ROOT_DIR creation

[NebelNidas]

Currently, this folder is created as soon as the FileUtils class gets loaded by the JVM:

jadx/jadx-core/src/main/java/jadx/core/utils/files/FileUtils.java

Lines 153 to 169 in 2807dc5

	private static final Path TEMP_ROOT_DIR = createTempRootDir();
	private static Path createTempRootDir() {
	try {
	String jadxTmpDir = System.getenv("JADX_TMP_DIR");
	Path dir;
	if (jadxTmpDir != null) {
	dir = Files.createTempDirectory(Paths.get(jadxTmpDir), "jadx-instance-");
	} else {
	dir = Files.createTempDirectory(JADX_TMP_INSTANCE_PREFIX);
	}
	dir.toFile().deleteOnExit();
	return dir;
	} catch (Exception e) {
	throw new JadxRuntimeException("Failed to create temp root directory", e);
	}
	}

Usually that's not a problem, but I'm currently encountering an issue on Windows where this behavior leads to a crash:

Caused by: jadx.core.utils.exceptions.JadxRuntimeException: Failed to create temp root directory
        at jadx.core.utils.files.FileUtils.createTempRootDir(FileUtils.java:165)
        at jadx.core.utils.files.FileUtils.<clinit>(FileUtils.java:151)
        ... 31 more
Caused by: java.nio.file.AccessDeniedException: C:\Windows\jadx-instance-3513248238493422666
        at jadx.core.utils.files.FileUtils.createTempRootDir(FileUtils.java:160)
        ... 32 more

Changing the JADX_TMP_DIR environment variable or the java.io.tmpdir system property surprisingly has no effect. I have no idea how that's possible, and didn't find any related info online, so until I find the root cause, it would be nice if you could just defer the folder creation until it's actually required by JADX for now.

If you want to reproduce the issue: Clone this branch and run ./gradlew test --tests '*DecompileTest' (requires JDK >=17). The astonishing thing is that it doesn't seem to fail when run through GitHub Actions, but I have been able to reproduce the crash on at least two physical and one virtual machine of mine (Windows 10 22H2, multiple JDK vendors). Any ideas?