feat: Instance Registration and Configuration (#2793)

* dev: remove default user

* dev: initiate licensing

* dev: remove migration file 0046

* feat: self hosted licensing initialize

* dev: instance licenses

* dev: change license response structure

* dev: add default properties and issue mention migration

* dev: reset migrations

* dev: instance configuration

* dev: instance configuration migration

* dev: update instance configuration model to take null and empty values

* dev: instance configuration variables

* dev: set default values

* dev: update instance configuration load

* dev: email configuration settings moved to database

* dev: instance configuration on instance bootup

* dev: auto instance registration script

* dev: instance admin

* dev: enable instance configuration and instance admin roles

* dev: instance owner fix

* dev: instance configuration values

* dev: fix instance permissions and serializer

* dev: fix email senders

* dev: remove deprecated variables

* dev: fix current site domain registration

* dev: update cors setup and local settings

* dev: migrate instance registration and configuration to manage commands

* dev: check email validity

* dev: update script to use manage command

* dev: default bucket creation script

* dev: instance admin routes and initial set of screens

* dev: admin api to check if the current user is admin

* dev: instance admin unique constraints

* dev: check magic link login

* dev: fix email sending for ssl

* dev: create instance activation route if the instance is not activated during startup

* dev: removed DJANGO_SETTINGS_MODULE from environment files and deleted auto bucket create script

* dev: environment configuration for backend

* dev: fix access token variable error

* feat: Instance Admin Panel: General Settings (#2792)

---------

Co-authored-by: pablohashescobar <nikhilschacko@gmail.com>
Co-authored-by: Prateek Shourya <prateekshourya29@gmail.com>

apiserver/plane/license/models/instance.py

@@ -0,0 +1,73 @@
+# Django imports
+from django.db import models
+from django.conf import settings
+
+# Module imports
+from plane.db.models import BaseModel
+from plane.db.mixins import AuditModel
+
+ROLE_CHOICES = (
+    (20, "Owner"),
+    (15, "Admin"),
+)
+
+
+class Instance(BaseModel):
+    # General informations
+    instance_name = models.CharField(max_length=255)
+    whitelist_emails = models.TextField(blank=True, null=True)
+    instance_id = models.CharField(max_length=25, unique=True)
+    license_key = models.CharField(max_length=256, null=True, blank=True)
+    api_key = models.CharField(max_length=16)
+    version = models.CharField(max_length=10)
+    # User information
+    primary_email = models.CharField(max_length=256)
+    primary_owner = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.SET_NULL,
+        null=True,
+        related_name="instance_primary_owner",
+    )
+    # Instnace specifics
+    last_checked_at = models.DateTimeField()
+    namespace = models.CharField(max_length=50, blank=True, null=True)
+    # telemetry and support
+    is_telemetry_enabled = models.BooleanField(default=True)
+    is_support_required = models.BooleanField(default=True)
+
+    class Meta:
+        verbose_name = "Instance"
+        verbose_name_plural = "Instances"
+        db_table = "instances"
+        ordering = ("-created_at",)
+
+
+class InstanceAdmin(BaseModel):
+    user = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.SET_NULL,
+        null=True,
+        related_name="instance_owner",
+    )
+    instance = models.ForeignKey(Instance, on_delete=models.CASCADE, related_name="admins")
+    role = models.PositiveIntegerField(choices=ROLE_CHOICES, default=15)
+
+    class Meta:
+        unique_together = ["instance", "user"]
+        verbose_name = "Instance Admin"
+        verbose_name_plural = "Instance Admins"
+        db_table = "instance_admins"
+        ordering = ("-created_at",)
+
+
+class InstanceConfiguration(BaseModel):
+    # The instance configuration variables
+    key = models.CharField(max_length=100, unique=True)
+    value = models.TextField(null=True, blank=True, default=None)
+
+    class Meta:
+        verbose_name = "Instance Configuration"
+        verbose_name_plural = "Instance Configurations"
+        db_table = "instance_configurations"
+        ordering = ("-created_at",)
+