📈(backend) introduce analytics

In this commit, we'll integrate a third-party service to track user events.
We start by using the `identify` method to track sign-ins and sign-ups.

Additionally, we use the `track` method to monitor custom events such as room
creation, access token generation, and logouts. This will provide us with
valuable data on current usage patterns.

The analytics library operates by opening a queue in a separate thread for
posting events, ensuring it remains non-blocking for the API. Let's test
this in a real-world scenario.

src/backend/core/analytics.py

@@ -0,0 +1,58 @@
+"""
+Meet analytics class.
+"""
+
+import uuid
+
+from django.conf import settings
+
+from june import analytics as jAnalytics
+
+
+class Analytics:
+    """Analytics integration
+
+    This class wraps the June analytics code to avoid coupling our code directly
+    with this third-party library. By doing so, we create a generic interface
+    for analytics that can be easily modified or replaced in the future.
+    """
+
+    def __init__(self):
+        key = getattr(settings, "ANALYTICS_KEY", None)
+
+        if key is not None:
+            jAnalytics.write_key = key
+
+        self._enabled = key is not None
+
+    def _is_anonymous_user(self, user):
+        """Check if the user is anonymous."""
+        return user is None or user.is_anonymous
+
+    def identify(self, user, **kwargs):
+        """Identify a user"""
+
+        if self._is_anonymous_user(user) or not self._enabled:
+            return
+
+        traits = kwargs.pop("traits", {})
+        traits.update({"email": user.email_anonymized})
+
+        jAnalytics.identify(user_id=user.sub, traits=traits, **kwargs)
+
+    def track(self, user, **kwargs):
+        """Track an event"""
+
+        if not self._enabled:
+            return
+
+        event_data = {}
+        if self._is_anonymous_user(user):
+            event_data["anonymous_id"] = str(uuid.uuid4())
+        else:
+            event_data["user_id"] = user.sub
+
+        jAnalytics.track(**event_data, **kwargs)
+
+
+analytics = Analytics()