Add devterm tools and TUI menu

devterm/tools/base64_tool.py

@@ -0,0 +1,12 @@
+import base64
+
+
+def encode_base64(data: str) -> str:
+    return base64.b64encode(data.encode("utf-8")).decode("utf-8")
+
+
+def decode_base64(data: str) -> str:
+    missing_padding = len(data) % 4
+    if missing_padding:
+        data += "=" * (4 - missing_padding)
+    return base64.b64decode(data.encode("utf-8")).decode("utf-8")