notification import/export (#413)

Co-authored-by: hay-kot <hay-kot@pm.me>

mealie/schema/backup.py

@@ -11,6 +11,7 @@ class BackupOptions(BaseModel):
     themes: bool = True
     groups: bool = True
     users: bool = True
+    notifications: bool = True
 
     class Config:
         schema_extra = {

mealie/schema/restore.py

@@ -31,3 +31,7 @@ class UserImport(ImportBase):
 
 class CustomPageImport(ImportBase):
     pass
+
+
+class NotificationImport(ImportBase):
+    pass