fix: Resolve issues and improve code quality in AnnotateComponent

[Swapnilden]

• Removed unused imports and corrected styleUrl property
• Refactored onSelectAnnotation and onFileChange methods for clarity
• Added error handling in the query method for fetch errors
• Extracted conditions into meaningful variables for readability
• Removed standalone property from @component decorator
• Defined type explicitly for annotations array
• Updated baseUrl handling for better security
• Improved error handling in search method when doc.annotation is null