All tests' meta/output/work directories are deleted and recreated unnecessarily

[jmuhlich]

When running nf-test list, or nf-test test on a specific list of tests, the entire sub-directory under .nf-test/tests/ is re-initialized to its original state. All generated test setup files and test outputs are deleted. This makes it very annoying to work on fixing tests as all output is deleted just by running nf-test list or running an unrelated test. Furthermore it makes parallelizing tests needlessly difficult -- an obvious trick like nf-test list --format=raw --silent | parallel nf-test test fails random tests due to the race condition of each instance potentially deleting files that other tests just wrote.

I believe the cause is that the directory re-initialization is run too aggressively even when the test case isn't going to be executed:

nf-test/src/main/java/com/askimed/nf/test/core/AbstractTest.java

Lines 105 to 108 in 9dafa52

	launchDir = initDirectory("Launch Directory", testDirectory, DIRECTORY_TESTS, getHash());
	metaDir = initDirectory("Meta Directory", launchDir, DIRECTORY_META);
	outputDir = initDirectory("Output Directory", launchDir, DIRECTORY_OUTPUT);
	workDir = initDirectory("Working Directory", launchDir, DIRECTORY_WORK);