Add tasks for all the new languages

Task/Variadic-function/Sidef/variadic-function-1.sidef

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+func print_all(*things) {
+    things.each { |x| say x };
+}

Task/Variadic-function/Sidef/variadic-function-2.sidef

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+print_all(4, 3, 5, 6, 4, 3);
+print_all(4, 3, 5);
+print_all("Rosetta", "Code", "Is", "Awesome!");

Task/Variadic-function/Sidef/variadic-function-3.sidef

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+var args = ["Rosetta", "Code", "Is", "Awesome!"];
+print_all(args...);