CreateDirIfNotExisted creates the quics folder if it does not exist.

get conflict dir path.

get new emptyfile in quicsDir, if not exist then create new emptyfile.

GetQuicsDirPath returns the path of the quics folder.

get temp dir path.

LocalAbsToRoot converts an absolute path to a relative path to the root ex) LocalAbsToRoot("/a/rootDir/c", "/a/rootDir") -> "/rootDir/c".

LocalRelToRoot converts a relative path to a relative path to the root ex) LocalRelToRoot("./b/c", "a/b") -> "/c".