Cleaner error handling

[germa89]

Improving error handling of non-available results.

Now, if you request a non-available data, something like this will show:

>>> nl_plwk = mapdl.post_processing.nodal_values('NL','PLWK')
CRITICAL - pymapdl_global -  logging - handle_exception - Uncaught exception
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/german.ayuso/pymapdl/.venv_macos/lib/python3.11/site-packages/ansys/mapdl/core/post.py", line 313, in nodal_values
    values = self._ndof_rst(item=item, it1num=comp)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/german.ayuso/pymapdl/.venv_macos/lib/python3.11/site-packages/ansys/mapdl/core/post.py", line 36, in wrapper
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/Users/german.ayuso/pymapdl/.venv_macos/lib/python3.11/site-packages/ansys/mapdl/core/post.py", line 768, in _ndof_rst
    raise ValueError(f"The results obtained with '{item},{it1num},{item2}' are empty.\n"
ValueError: The results obtained with 'NL,PLWK,' are empty.
You can check the MAPDL output by issuing:

mapdl.run('*vget,temp_array, node, , NL, PLWK, ')

And if you follow the message and issue mapdl.run('*vget,temp_array, node, , NL, PLWK, '), you obtain:

>>> mapdl.run('*vget,temp_array, node, , NL, PLWK, ')
CRITICAL - pymapdl_global -  logging - handle_exception - Uncaught exception
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/german.ayuso/pymapdl/.venv_macos/lib/python3.11/site-packages/ansys/mapdl/core/mapdl.py", line 2907, in run
    self._raise_errors(text)
  File "/Users/german.ayuso/pymapdl/.venv_macos/lib/python3.11/site-packages/ansys/mapdl/core/mapdl.py", line 3850, in _raise_errors
    raise MapdlCommandIgnoredError(text)
ansys.mapdl.core.errors.MapdlCommandIgnoredError: VECTOR GET OPERATION  temp_array  VECTOR LENGTH=   22612
 NAME= NODE         0  NL    PLWK

 *** WARNING ***                         CP =       9.312   TIME= 04:34:42
 The requested NL data is not available.  The *VGET command is ignored.

Ignore these messages by setting 'ignore_errors'=True

Close #1275

[codecov]

Codecov Report

Merging #1935 (ba7ec72) into main (d21760a) will increase coverage by 7.93%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #1935      +/-   ##
==========================================
+ Coverage   78.07%   86.00%   +7.93%     
==========================================
  Files          44       44              
  Lines        7878     7877       -1     
==========================================
+ Hits         6151     6775     +624     
+ Misses       1727     1102     -625     

[clatapie]

LGTM