Implemented Funge-98 IO procedures

tests/defaultIO.nim

@@ -0,0 +1,25 @@
+discard """
+  input: "ab1234cd12f"
+  output: '''
+[Suite] defaultIO
+gh789
+  '''
+"""
+
+import unittest
+
+include ../src/defaultIO
+
+suite "defaultIO":
+  test "defaultCharacterInput":
+    check defaultCharacterInput() == 'a'.int
+    check defaultCharacterInput() == 'b'.int
+    check defaultCharacterInput() == '1'.int
+  test "defaultDecimalInput":
+    check defaultDecimalInput() == 234
+    check defaultCharacterInput() == 'c'.int
+  test "defaultCharacterOutput":
+    defaultCharacterOutput('g'.int)
+    defaultCharacterOutput('h'.int)
+  test "defaultDecimalOutput":
+    defaultDecimalOutput(789)