[Multi-User]: Part 0 - Add support for logging in with Google (#487)

* Add concept of user authentication to the request session via GoogleUser

src/database/models/__init__.py

@@ -0,0 +1,53 @@
+import uuid
+
+from django.db import models
+from django.contrib.auth.models import AbstractUser
+
+
+class KhojUser(AbstractUser):
+    uuid = models.UUIDField(models.UUIDField(default=uuid.uuid4, editable=False))
+
+
+class GoogleUser(models.Model):
+    user = models.OneToOneField(KhojUser, on_delete=models.CASCADE)
+    sub = models.CharField(max_length=200)
+    azp = models.CharField(max_length=200)
+    email = models.CharField(max_length=200)
+    name = models.CharField(max_length=200)
+    given_name = models.CharField(max_length=200)
+    family_name = models.CharField(max_length=200)
+    picture = models.CharField(max_length=200)
+    locale = models.CharField(max_length=200)
+
+    def __str__(self):
+        return self.name
+
+
+class Configuration(models.Model):
+    user = models.OneToOneField(KhojUser, on_delete=models.CASCADE)
+
+
+class NotionConfig(models.Model):
+    token = models.CharField(max_length=200)
+    compressed_jsonl = models.CharField(max_length=300)
+    embeddings_file = models.CharField(max_length=300)
+    config = models.OneToOneField(Configuration, on_delete=models.CASCADE)
+
+
+class GithubConfig(models.Model):
+    pat_token = models.CharField(max_length=200)
+    compressed_jsonl = models.CharField(max_length=300)
+    embeddings_file = models.CharField(max_length=300)
+    config = models.OneToOneField(Configuration, on_delete=models.CASCADE)
+
+
+class GithubRepoConfig(models.Model):
+    name = models.CharField(max_length=200)
+    owner = models.CharField(max_length=200)
+    branch = models.CharField(max_length=200)
+    github_config = models.ForeignKey(GithubConfig, on_delete=models.CASCADE)
+
+
+class ConversationProcessorConfig(models.Model):
+    conversation = models.JSONField()
+    enable_offline_chat = models.BooleanField(default=False)