Add tasks for all the new languages

Task/Collections/Sidef/collections-4.sidef

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+# creating a struct
+struct Person {
+    String name,
+    Number age,
+    String sex
+}
+
+var a = Person("John Smith", 41, :man)
+
+a.age += 1                  # increment age
+a.name = "Dr. #{a.name}"    # update name
+
+say a.name          #=> "Dr. John Smith"
+say a.age           #=> 42
+say a.sex           #=> "man"