Refactor imports in admin.py and update MAC address handling in views.py to improve code clarity and error handling

api/admin.py

@@ -1,8 +1,5 @@
-from typing import Any
 from django.contrib import admin
 from django.contrib.auth.admin import UserAdmin as BaseUserAdmin
-from django.forms.models import ModelForm
-from django.http.request import HttpRequest
 from api.models import User, Atoll, Island, TemporaryUser
 from django.contrib.auth.models import Permission