fix: ensure returned resource ids are integers (#651)

##### SUMMARY

The documentation states that all our returned resource ids are
integers, this change aligns our modules with the docs.

The impact of this change should be minimal, as ids are used for
identification purposes by directly forwarding the values (no
transformation of the data is done).

##### ISSUE TYPE

- Bugfix Pull Request


##### COMPONENT NAME

All modules

plugins/modules/image_info.py

@@ -132,7 +132,7 @@ class AnsibleHCloudImageInfo(AnsibleHCloud):
 
             tmp.append(
                 {
-                    "id": str(image.id),
+                    "id": image.id,
                     "status": image.status,
                     "type": image.type,
                     "name": image.name,