fix(client): Handle 'data' key in paginate_all for get_all parameter

The paginate_all method was only checking for "results" key in API
responses, but some GitGuardian API endpoints return data using a
"data" key instead. This caused get_all=True to fail by returning
empty lists.

Added support for both response formats:
- {"results": [...]} (existing)
- {"data": [...]} (newly added)

This fixes MCP tool calls with get_all=True parameter for endpoints
like list_repo_incidents, list_repo_occurrences, and remediate_secret_incidents.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: timothedelion

packages/gg_api_core/src/gg_api_core/client.py

@@ -567,6 +567,8 @@ async def paginate_all(self, endpoint: str, params: Dict[str, Any] = None) -> Li
             # Add items to our collection
             if isinstance(data, dict) and "results" in data:
                 items = data.get("results", [])
+            elif isinstance(data, dict) and "data" in data:
+                items = data.get("data", [])
             elif isinstance(data, list):
                 items = data
             else: