add cetacean cipher encoder and decoder operations, tests. Update .gitignore to exclude idea generated files

tests/operations/tests/CetaceanCipherDecode.mjs

@@ -0,0 +1,22 @@
+/**
+ * CetaceanCipher Encode tests
+ *
+ * @author dolphinOnKeys
+ * @copyright Crown Copyright 2022
+ * @licence Apache-2.0
+ */
+import TestRegister from "../../lib/TestRegister.mjs";
+
+TestRegister.addTests([
+    {
+        name: "Cetacean Cipher Decode",
+        input: "EEEEEEEEEeeEEEEe EEEEEEEEEeeEEEeE EEEEEEEEEeeEEEee EEeeEEEEEeeEEeee",
+        expectedOutput: "a b c で",
+        recipeConfig: [
+            {
+                op: "Cetacean Cipher Decode",
+                args: []
+            },
+        ],
+    }
+]);