BUG: Fix XML loading to convert numeric VR values to proper Python types

pydicom 3.0+ requires numeric VR types (US, SS, UL, SL, FD, FL) to be actual integers/floats, not strings. Updated _load_xml_dataset to convert string values from XML to the appropriate Python type based on VR.

This fixes test_load_xml_response which was failing with 'A value of type str cannot be assigned to a tag with VR US'.

Author: jamesobutler

src/dicomweb_client/web.py

@@ -74,6 +74,16 @@ def _load_xml_dataset(dataset: Element) -> pydicom.dataset.Dataset:
                 value = [v.text.strip() for v in value]
             else:
                 value = None
+            
+            # Convert string values to appropriate Python types for numeric VRs
+            # to satisfy pydicom 3.0+ stricter type validation
+            if value is not None and vr in ('US', 'SS', 'UL', 'SL', 'FD', 'FL'):
+                if isinstance(value, list):
+                    value = [int(v) if vr in ('US', 'SS', 'UL', 'SL') else float(v) 
+                             for v in value]
+                else:
+                    value = int(value) if vr in ('US', 'SS', 'UL', 'SL') else float(value)
+        
         setattr(ds, keyword, value)
     return ds