Fix/danial/improve feedback selection and sidebar

Improve Chat Feedback System UX and Fix Critical Bugs

Changes

🐛 Bug Fixes

• Fixed text selection detection: Resolved issue where feedback buttons wouldn't appear for selections within nested HTML elements
• Fixed memory leaks: Added proper subscription cleanup to prevent duplicate event listeners
• Fixed feedback button positioning: Improved accuracy of feedback button placement relative to text selections

🎨 UX Improvements

• Added selection delay: Implemented 300ms delay before showing feedback buttons to prevent accidental triggers
• Improved visual design: Updated feedback button styling with proper hover states and accessibility
• Personalized feedback text: Added "user marked this text" message for feedback without comments
• **When the user opens a session and there is no comment the the sidebar is closed by default.

🌐 Internationalization

• Added markedText translation key across all supported languages (EN, ES, FR, NL)