Tools to convert ONNX files (NCHW) to TensorFlow format (NHWC)

There is replacement options for some operations like Asin and PReLU. However, these options are separated in argument parsing and parameter passing, which make redundant and duplicated code parts. In this PR, those lines are simplified by using single option replace_to_pseudo_operators. If user give the names of target operation as list like ["acos", "hardswish"], each operator is replaced to pseudo operators same as before. I didn't change the logic itself, just refactoring for future in case more pseudo operators are added.

-rtpo, --replace_to_pseudo_operators
  Replace list of operators to pseudo operators.
  Full name of the target operators should be given.
  Currently supported operators :
  Asin, Acos, Abs, PReLU, LeakyReLU, Power, GatherND, Neg, HardSwish, Erf

• Simplifying operation replacement procedure to pseudo operation by @Hyunseok-Kim0 in https://github.com/PINTO0309/onnx2tf/pull/165

Full Changelog: https://github.com/PINTO0309/onnx2tf/compare/1.5.38...1.5.40