scripted-diff: Use Flags enum in AddArg()

-BEGIN VERIFY SCRIPT-
sed -i 's/const bool debug_only,/unsigned int flags, &/' src/util/system.h src/util/system.cpp
sed -i -E 's/(true|false), OptionsCategory::/ArgsManager::ALLOW_ANY, &/' $(git grep --files-with-matches 'AddArg(' src)
-END VERIFY SCRIPT-

src/test/getarg_tests.cpp

@@ -36,7 +36,7 @@ static void SetupArgs(const std::vector<std::string>& args)
 {
     gArgs.ClearArgs();
     for (const std::string& arg : args) {
-        gArgs.AddArg(arg, "", false, OptionsCategory::OPTIONS);
+        gArgs.AddArg(arg, "", ArgsManager::ALLOW_ANY, false, OptionsCategory::OPTIONS);
     }
 }