Add tasks for all the new languages

Task/Empty-string/FreeBASIC/empty-string.freebasic

@@ -0,0 +1,17 @@
+' FB 1.05.0 Win64
+
+Sub IsEmpty(s As String)
+   If Len(s) = 0 Then
+     Print "String is empty"
+   Else
+     Print "String is not empty"
+   End If
+End Sub
+
+Dim s As String  ' implicitly assigned an empty string
+IsEmpty(s)
+Dim t As String = "" ' explicitly assigned an empty string
+IsEmpty(t)
+Dim u As String = "not empty"
+IsEmpty(u)
+Sleep