fix help

[seanpearsonuk]

recent sonar clean-up; multiple replacement of repr (due to shadowing) accidentally went too far.

Without the change, we raise and unhandled exception:

>>> import ansys.fluent.core as pf
>>> s = pf.launch_fluent(start_transcript=False)
>>> help(s.file.read_case)
Help on read_case in module ansys.fluent.core.solver.flobject object:

class read_case(Command)
 |  read_case(name: str = None, parent=None)
 |
 |  'read_case' command.
 |
 |  Parameters
 |  ----------
 |      file_name : str
 |          'file_name' child.
 |      pdf_file_name : str
 |          'pdf_file_name' child.