ssdm-13365: moved lib-file-download into proper folder

...ceTest/java/ch/ethz/sis/filetransfer/RecordingLogger.java

...ceTest/java/ch/ethz/sis/filetransfer/StreamTestUtils.java

...rceTest/java/ch/ethz/sis/filetransfer/TestAssertions.java

...Test/java/ch/ethz/sis/filetransfer/TestChunkProvider.java

...ava/ch/ethz/sis/filetransfer/TestConcurrencyProvider.java

...est/java/ch/ethz/sis/filetransfer/TestDownloadItemId.java

...ethz/sis/filetransfer/TestDownloadItemIdDeserializer.java

...h/ethz/sis/filetransfer/TestDownloadItemIdSerializer.java

...Test/java/ch/ethz/sis/filetransfer/TestDownloadStore.java

...ceTest/java/ch/ethz/sis/filetransfer/TestInputStream.java

.../sourceTest/java/ch/ethz/sis/filetransfer/TestLogger.java

...ceTest/java/ch/ethz/sis/filetransfer/TestUserSession.java

...java/ch/ethz/sis/filetransfer/TestUserSessionManager.java

lib-file-download/sourceTest/java/tests.xml

lib-file-download/sourceTest/test-files/testFile1.txt

lib-file-download/sourceTest/test-files/testFile2.txt

...e-download/sourceTest/test-files/testFolder/testFile3.txt

...e-download/sourceTest/test-files/testFolder/testFile4.txt

...ourceTest/test-files/testFolder/testFolder2/testFile5.txt