NetCDF annotation time filter should not be available in the release

Since netcdftime python module is not packaged in the ParaView release, this plugin should not be available, as using the filter will fail with :

Traceback (most recent call last):
  File "<string>", line 22, in <module>
  File "<string>", line 2, in RequestData
ModuleNotFoundError: No module named 'netcdftime'
Failed to evaluate expression '"On %02i.%02i.%02i at %02i:%02i" % (Date[0], Date[1], Date[2], Date[3], Date[4])'. The following exception stack should provide additional developer specific information. This typically implies a malformed expression. Verify that the expression is valid.

Variables in current scope are ['input', 'time_value', 't_value', 'time_steps', 't_steps', 'time_range', 't_range', 'time_index', 't_index'] 

Traceback (most recent call last):
  File "/home/glow/work/paraview/others/ParaView-5.8.0-MPI-Linux-Python3.7-64bit/lib/python3.7/site-packages/paraview/detail/annotation.py", line 95, in execute
    result = calculator.compute(inputs, expression, ns=ns)
  File "/home/glow/work/paraview/others/ParaView-5.8.0-MPI-Linux-Python3.7-64bit/lib/python3.7/site-packages/paraview/detail/calculator.py", line 146, in compute
    retVal = eval(subEx, globals(), mylocals)
  File "<string>", line 1, in <module>
NameError: name 'Date' is not defined

@ben.boeckel @cory.quammen @jpouderoux