Limitation in file path size for converter.py

We can't convert .med to .slf with converter.py if the path is too long :

LINE:  11 ERROR: QUOTE MISSING AT THE END OF THE STRING
 OR STRING TOO LONG ...

 ************************
 * DAMOCLES STOPPED     *
 ************************

 -----------------------------------------
 - ERROR IN THE STEERING FILE            -
 -----------------------------------------

For create_mesh processing we need to explicit temporary path so path size is not too long.

Note:

The limitation seems to be 72 characters

This is an issue for unit test because we can't be sure that temporary directory won't exceed this limitation.