VS: Fix MANIFESTUAC link flag map to .vcxproj elements

Add special parsing of the flags given in `/MANIFESTUAC:"..."` in order
to map them correctly to `.vcxproj` elements.

Keep the old incorrect flag table entries for `uiAccess` and `level`
flags for compatibility even though they do not really exist.

Fixes: #16563

Source/cmVisualStudioGeneratorOptions.h

@@ -77,6 +77,8 @@ public:
 
   void FixCudaCodeGeneration();
 
+  void FixManifestUACFlags();
+
   bool IsDebug() const;
   bool IsWinRt() const;
   bool IsManaged() const;