Fix TestWriteBasicAttributes for all cases

It seems TestWriteBasicAttributes did not correctly write
the attributes. The broad exception handling seems to have hidden
this issue even.  Make sure the attributes with the correct value
get written, and check for unexpected and expected IM errors
in the per-attribute results specifically.

src/controller/python/test/test_scripts/base.py

@@ -1193,16 +1193,16 @@ class AttributeWriteRequest:
         failed_attribute_write = []
         for req in requests:
             try:
-                try:
-                    await self.devCtrl.WriteAttribute(nodeid, [(endpoint, req.attribute, 0)])
-                    if req.expected_status != IM.Status.Success:
-                        raise AssertionError(
-                            f"Write attribute {req.attribute.__qualname__} expects failure but got success response")
-                except ChipStackError as ex:
-                    if req.expected_status != IM.Status.Success:
-                        continue
-                    else:
-                        raise ex
+                # Errors tested here is in the per-attribute result list (type AttributeStatus)
+                write_res = await self.devCtrl.WriteAttribute(nodeid, [(endpoint, req.attribute(req.value))])
+                status = write_res[0].Status
+                if req.expected_status != status:
+                    raise AssertionError(
+                        f"Write attribute {req.attribute.__qualname__} expects {req.expected_status} but got {status}")
+
+                # Only execute read tests where write is successful.
+                if req.expected_status != IM.Status.Success:
+                    continue
 
                 res = await self.devCtrl.ReadAttribute(nodeid, [(endpoint, req.attribute)])
                 val = res[endpoint][req.cluster][req.attribute]