Support Ninja generator for MSVC
Support Ninja generator for MSVC

Also increases the number of directory candidates for finding Qt,
as there is not yet any msvc2019 variant but VS 2019 is binary
compatible to VS 2017.

MITK/MITK,fmilano/mitk,MITK/MITK,fmilano/mitk,MITK/MITK,MITK/MITK,fmilano/mitk,fmilano/mitk,MITK/MITK,fmilano/mitk,MITK/MITK,fmilano/mitk,fmilano/mitk