ENH: put the wavelet enum in its own namespace

Code/MultiScale/otbWaveletGenerator.cxx

Code/MultiScale/otbWaveletGenerator.h

Code/MultiScale/otbWaveletHighPassOperator.h

Code/MultiScale/otbWaveletLowPassOperator.h

Code/MultiScale/otbWaveletOperator.h

Code/MultiScale/otbWaveletOperatorBase.h

Code/MultiScale/otbWaveletOperatorBase.txx

Testing/Code/MultiScale/otbWaveletFilterBank.cxx

Testing/Code/MultiScale/otbWaveletFilterBankNew.cxx

Testing/Code/MultiScale/otbWaveletInverseFilterBankNew.cxx

Testing/Code/MultiScale/otbWaveletInverseTransformNew.cxx

Testing/Code/MultiScale/otbWaveletOperator.cxx

Testing/Code/MultiScale/otbWaveletOperatorNew.cxx

...g/Code/MultiScale/otbWaveletPacketInverseTransformNew.cxx

Testing/Code/MultiScale/otbWaveletPacketTransform.cxx

Testing/Code/MultiScale/otbWaveletPacketTransformNew.cxx

Testing/Code/MultiScale/otbWaveletTransform.cxx

Testing/Code/MultiScale/otbWaveletTransformNew.cxx