Added an option to enable/disable translation of hashtags

Fix tweet containing '/' when text to be translated is sent via DeepL URL

• More stable injection of the "Translate Tweet with DeepL" button
• Translated tweet content now includes hashtag and emojis
• Settings
  • Change translation target language
  • If DeepL API key is provided, translation will automatically appear under the tweet like the regular "Translate Tweet" button.
    See https://www.deepl.com/fr/pro-api?cta=header-pro-api for information about DeepL API