Performance optimizations and bug fixes

[trislee]

• Modified langdetect detect method to decrease run-time
• Fixed indentation error in transform_info
• Prototyped removal of offset in transform_all_untransformed
  • This change needs modifications: it fails for the first batch, since the batch is already computed, so that only one ScraperResult.date is greater than or equal to max(batch, key=lambda v: v.date).date, so only one post is transformed.
• Originally modified TelegramTelethonTransformer to have a self.client attribute, but this caused the transformer tests to fail, since having a TelegramTelethonScraper already initialized while initializing a TelegramTelethonTransformer causes the Telethon session database to be locked. This could be addressed by deleting the controller object in tests/transformer/telegram_telethon.py