Display meaningful error message if temporary path would be too long for OS
Certain setups (Windows ...) don't allow long path names. If FLOW3 is installed somewhere deep in the file structure, the path + file name for the caches and temp directory can become too long.
Currently this results in an exception thrown when trying to write to that directory (see #3550) but this could be checked earlier, when the temp directory is created in Utility\Environment. A meaningful error message would help to configure FLOW3 correctly.