engine: add parse_location stub

engine.py

@@ -54,6 +54,16 @@ def format_location(location: EncodedLocation) -> str:
     return ";".join([f"{a}:{','.join(map(str, b))}" for (a, b) in location])
 
 
+def parse_location(location: str) -> EncodedLocation:
+    """Parse a location string into an EncodedLocation."""
+
+    # Stub
+    return [
+        (5., [1., 2., 3.]),
+        (6., [4., 5., 6.]),
+    ]
+
+
 def main():
     """Testing."""
     print("Running query...")