[Multi-User Part 8]: Make conversation processor settings server-wide (#529)

- Rather than having each individual user configure their conversation settings, allow the server admin to configure the OpenAI API key or offline model once, and let all the users re-use that code.
- To configure the settings, the admin should go to the `django/admin` page and configure the relevant chat settings. To create an admin, run `python3 src/manage.py createsuperuser` and enter in the details. For simplicity, the email and username should match.
- Remove deprecated/unnecessary endpoints and views for configuring per-user chat settings

src/database/migrations/0010_chatmodeloptions_and_more.py

@@ -0,0 +1,83 @@
+# Generated by Django 4.2.4 on 2023-11-01 17:41
+
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("database", "0009_khojapiuser"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="ChatModelOptions",
+            fields=[
+                ("id", models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name="ID")),
+                ("created_at", models.DateTimeField(auto_now_add=True)),
+                ("updated_at", models.DateTimeField(auto_now=True)),
+                ("max_prompt_size", models.IntegerField(blank=True, default=None, null=True)),
+                ("tokenizer", models.CharField(blank=True, default=None, max_length=200, null=True)),
+                ("chat_model", models.CharField(blank=True, default=None, max_length=200, null=True)),
+                (
+                    "model_type",
+                    models.CharField(
+                        choices=[("openai", "Openai"), ("offline", "Offline")], default="openai", max_length=200
+                    ),
+                ),
+            ],
+            options={
+                "abstract": False,
+            },
+        ),
+        migrations.CreateModel(
+            name="OfflineChatProcessorConversationConfig",
+            fields=[
+                ("id", models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name="ID")),
+                ("created_at", models.DateTimeField(auto_now_add=True)),
+                ("updated_at", models.DateTimeField(auto_now=True)),
+                ("enabled", models.BooleanField(default=False)),
+            ],
+            options={
+                "abstract": False,
+            },
+        ),
+        migrations.CreateModel(
+            name="OpenAIProcessorConversationConfig",
+            fields=[
+                ("id", models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name="ID")),
+                ("created_at", models.DateTimeField(auto_now_add=True)),
+                ("updated_at", models.DateTimeField(auto_now=True)),
+                ("api_key", models.CharField(max_length=200)),
+            ],
+            options={
+                "abstract": False,
+            },
+        ),
+        migrations.CreateModel(
+            name="UserConversationConfig",
+            fields=[
+                ("id", models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name="ID")),
+                ("created_at", models.DateTimeField(auto_now_add=True)),
+                ("updated_at", models.DateTimeField(auto_now=True)),
+                (
+                    "setting",
+                    models.ForeignKey(
+                        blank=True,
+                        default=None,
+                        null=True,
+                        on_delete=django.db.models.deletion.CASCADE,
+                        to="database.chatmodeloptions",
+                    ),
+                ),
+                (
+                    "user",
+                    models.OneToOneField(on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL),
+                ),
+            ],
+            options={
+                "abstract": False,
+            },
+        ),
+    ]