CMake: Update FindNpm module and usage

FindNpm REQUIRE functionality was not provided by FindNpm.cmake.
UpdatedUpdated FindNpm to extract version, global node_modules
directory, and to fail if REQUIRE was set and npm was not found.

Signed-off-by: Noel Eck <noel.eck@intel.com>

CMakeLists.txt

@@ -151,11 +151,6 @@ if (BUILDSWIGNODE)
   find_package (Node REQUIRED)
   if (BUILDTESTS)
     find_package (Npm REQUIRED)
-    if(NPM_EXECUTABLE)
-        message(STATUS "NPM Executable found at: ${NPM_EXECUTABLE}")
-    else()
-        message(FATAL_ERROR "Please install NPM first, you can't run tests without it")
-    endif()
   endif (BUILDTESTS)
 endif (BUILDSWIGNODE)