add CoreLightningRestWallet (#362)

* add CoreLightningRestWallet

* add macaroon loader

* add correct config

cashu/lightning/macaroon.py

@@ -0,0 +1,34 @@
+import base64
+
+
+def load_macaroon(macaroon: str) -> str:
+    """Returns hex version of a macaroon encoded in base64 or the file path.
+
+    :param macaroon: Macaroon encoded in base64 or file path.
+    :type macaroon: str
+    :return: Hex version of macaroon.
+    :rtype: str
+    """
+
+    # if the macaroon is a file path, load it and return hex version
+    if macaroon.split(".")[-1] == "macaroon":
+        try:
+            with open(macaroon, "rb") as f:
+                macaroon_bytes = f.read()
+                return macaroon_bytes.hex()
+        except FileNotFoundError:
+            raise Exception(f"Macaroon file not found: {macaroon}")
+    else:
+        # if macaroon is a provided string
+        # check if it is hex, if so, return
+        try:
+            bytes.fromhex(macaroon)
+            return macaroon
+        except ValueError:
+            pass
+        # convert the bas64 macaroon to hex
+        try:
+            macaroon = base64.b64decode(macaroon).hex()
+        except Exception:
+            pass
+    return macaroon