Refactor Docker setup and add mock data support

- Updated .dockerignore and .gitignore for better file management.
- Introduced .env.example for environment variable configuration.
- Added docker-compose.dev.yml for development with mock data and live reload.
- Enhanced Dockerfile to include necessary dependencies and entrypoint script.
- Created mock_data.py to provide sample data for testing without OpenStack/Prometheus.
- Added unit tests for template filters in dashboard.
- Cleaned up various files for consistency and improved readability.

dashboard/prometheus_utils/query.py

@@ -1,16 +1,16 @@
-import requests
-
-from watcher_visio.settings import PROMETHEUS_URL
-
-def query_prometheus(query: str) -> str | list[str]:
-    url = f"{PROMETHEUS_URL}/api/v1/query"
-    params = {
-        "query": query,
-    }
-    response = requests.get(url=url, params=params)
-    response.raise_for_status()
-    result = response.json()["data"]["result"]
-    if len(result) > 1:
-        return result[0]["value"][1]
-    else:
-        return result[0]["values"]
+import requests
+
+from watcher_visio.settings import PROMETHEUS_URL
+
+def query_prometheus(query: str) -> str | list[str]:
+    url = f"{PROMETHEUS_URL}/api/v1/query"
+    params = {
+        "query": query,
+    }
+    response = requests.get(url=url, params=params)
+    response.raise_for_status()
+    result = response.json()["data"]["result"]
+    if len(result) > 1:
+        return result
+    else:
+        return result[0]["value"][1]