add to_dict dispatch on adapter

Author: LarsKue

bayesflow/adapters/adapter.py

@@ -755,3 +755,10 @@ def to_array(
         )
         self.transforms.append(transform)
         return self
+
+    def to_dict(self):
+        from .transforms import ToDict
+
+        transform = ToDict()
+        self.transforms.append(transform)
+        return self