Fix `FileReadingMessageSource` to deal with canonical files

[artembilan]

We are observing failures on DOS-based operating systems like:

expected: C:\Users\RUNNER~1\AppData\Local\Temp\f1
 but was: C:\Users\runneradmin\AppData\Local\Temp\f1

So, FileUtils.newFileInDirectoryIfValid() deals with canonical files:

File file = new File(directory.getCanonicalFile(), fileName);

but the FileReadingMessageSource does not:

for (File file : filteredFiles) {
	this.toBeReceived.add(new DirFile(file, directory));
}