Added is_candidate_object

- Added `is_candidate_object` function that will check if the active
  object is a mesh type or not. Since the addon can only operate on a
  mesh, this is necessary

- If the active object is null, this will return False

stopmagic/functions/is_candidate_object.py

@@ -0,0 +1,11 @@
+from __future__ import annotations
+import bpy
+
+
+def is_candidate_object(context: bpy.types.Context | None) -> bool:
+    if context is None:
+        context = bpy.context
+    if context.view_layer.objects.active is None:
+        return False
+    else:
+        return context.view_layer.objects.active.type == "MESH"