Fix center and zoom map parameters to allow int or float values (#625)

* Upgrade center, zoom map params to floats

* Explicitly allow either int, float for center, zoom map params

Author: leehart

malariagen_data/anoph/map_params.py

@@ -7,13 +7,13 @@
 from typing_extensions import Annotated, TypeAlias
 
 center: TypeAlias = Annotated[
-    Tuple[int, int],
+    Tuple[Union[int, float], Union[int, float]],
     "Location to center the map.",
 ]
 
 center_default: center = (-2, 20)
 
-zoom: TypeAlias = Annotated[int, "Initial zoom level."]
+zoom: TypeAlias = Annotated[Union[int, float], "Initial zoom level."]
 
 zoom_default: zoom = 3