Search also for Qt plugins with CMAKE_SHARED_MODULE_SUFFIX.
Search also for Qt plugins with CMAKE_SHARED_MODULE_SUFFIX.

This fixes issues with missing plug-ins on Mac where .so is used for
plug-ins.

lsanzdiaz/MITK-BiiG,lsanzdiaz/MITK-BiiG,lsanzdiaz/MITK-BiiG,nocnokneo/MITK,iwegner/MITK,danielknorr/MITK,fmilano/mitk,rfloca/MITK,danielknorr/MITK,nocnokneo/MITK,nocnokneo/MITK,nocnokneo/MITK,fmilano/mitk,nocnokneo/MITK,fmilano/mitk,rfloca/MITK,lsanzdiaz/MITK-BiiG,rfloca/MITK,danielknorr/MITK,nocnokneo/MITK,MITK/MITK,MITK/MITK,iwegner/MITK,RabadanLab/MITKats,fmilano/mitk,danielknorr/MITK,nocnokneo/MITK,lsanzdiaz/MITK-BiiG,RabadanLab/MITKats,lsanzdiaz/MITK-BiiG,RabadanLab/MITKats,MITK/MITK,iwegner/MITK,RabadanLab/MITKats,fmilano/mitk,rfloca/MITK,fmilano/mitk,RabadanLab/MITKats,rfloca/MITK,NifTK/MITK,lsanzdiaz/MITK-BiiG,NifTK/MITK,lsanzdiaz/MITK-BiiG,RabadanLab/MITKats,iwegner/MITK,rfloca/MITK,NifTK/MITK,MITK/MITK,MITK/MITK,iwegner/MITK,danielknorr/MITK,NifTK/MITK,NifTK/MITK,danielknorr/MITK,NifTK/MITK,fmilano/mitk,danielknorr/MITK,MITK/MITK,iwegner/MITK,rfloca/MITK