Merge pull request #15351 from philippefoubert:pr_ximea

* Fix the detection of XIMEA on Windows (when it has been installed by another user with administrative privileges, for example).

* Change the flow: we first try HKEY_CURRENT_USER key and, if empty, then try HKEY_LOCAL_MACHINE

modules/videoio/cmake/detect_ximea.cmake

 if(NOT HAVE_XIMEA)
   if(WIN32)
     get_filename_component(regpath "[HKEY_CURRENT_USER\\Software\\XIMEA\\CamSupport\\API;Path]" ABSOLUTE)
+    if(NOT EXISTS ${regpath})
+      get_filename_component(regpath "[HKEY_LOCAL_MACHINE\\SOFTWARE\\XIMEA\\API_SoftwarePackage;Path]" ABSOLUTE)
+    endif()
   endif()
   if(X86_64)
     set(lib_dir "x64")