Refactor code for consistency and readability

- Standardized string quotes across multiple files to use double quotes for consistency.
- Improved formatting of JSON dumps in mock data for better readability.
- Enhanced the structure of various functions and data definitions for clarity.
- Updated test cases to reflect changes in data structure and ensure accuracy.

dashboard/mock_data.py

@@ -1,4 +1,5 @@
 """Mock context for dashboard when USE_MOCK_DATA is enabled (no OpenStack/Prometheus)."""
+
 import json
 
 
@@ -35,15 +36,17 @@ def get_mock_context():
             "scope": "Full Cluster",
             "cpu_weight": "1.0",
             "ram_weight": "1.0",
-            "migrations": json.dumps([
-                {
-                    "instanceName": "instance-1",
-                    "source": "compute-0",
-                    "destination": "compute-3",
-                    "flavor": "m1.small",
-                    "impact": "Low",
-                }
-            ]),
+            "migrations": json.dumps(
+                [
+                    {
+                        "instanceName": "instance-1",
+                        "source": "compute-0",
+                        "destination": "compute-3",
+                        "flavor": "m1.small",
+                        "impact": "Low",
+                    }
+                ]
+            ),
             "host_labels": json.dumps(host_labels),
             "cpu_current": json.dumps(cpu_current),
             "cpu_projected": json.dumps(cpu_projected),