feat(bounding-box): add bounding box highlight support

[dlasecki-box]

This PR adds the ability to display and interact with bounding box highlights on documents. Bounding boxes are rectangular overlays that can be used to highlight specific regions of interest (e.g., detected text regions, search results, AI predictions).

Key features:

• View Mode Switching: Introduces a new viewMode option to the annotator interface that toggles between annotations (default) and boundingBoxes modes. These modes are mutually exclusive - when in bounding boxes mode, traditional annotation tools are hidden, and vice versa.
• Bounding Box Rendering: Display rectangular highlights with coordinates on specific pages
• Selection & Navigation: Click to select bounding boxes, with built-in prev/next navigation
• Auto-scroll: Automatically scrolls to the selected bounding box

Possible usage on the client side:

// Set bounding boxes 
annotator.setBoundingBoxHighlights([                                                                                                                                                                                                             
    {                                                                                                                                                                                                                                              
      id: 'box-1',                                                                                                                                                                                                                                 
      x: 100,                                                                                                                                                                                                                                      
      y: 200,                                                                                                                                                                                                                                      
      width: 300,                                                                                                                                                                                                                                  
      height: 50,                                                                                                                                                                                                                                  
      pageNumber: 1                                                                                                                                                                                                                                
    },                                                                                                                                                                                                                                             
    {                                                                                                                                                                                                                                              
      id: 'box-2',                                                                                                                                                                                                                                 
      x: 150,                                                                                                                                                                                                                                      
      y: 400,                                                                                                                                                                                                                                      
      width: 250,                                                                                                                                                                                                                                  
      height: 75,                                                                                                                                                                                                                                  
      pageNumber: 2                                                                                                                                                                                                                                
    }                                                                                                                                                                                                                                              
  ]);  

// Switch to bounding boxes view mode                                                                                                                                                                                                            
annotator.setViewMode('boundingBoxes');
                                                                                                                                                                                                                                                   
// Programmatically select and scroll to a bounding box                                                                                                                                                                                          
annotator.selectBoundingBoxHighlight('box-1');         

[Lindar90]

1 major note regarding cleaning up the selected bbox Highlight

[Lindar90]

Minor:
Let's use enum: ViewMode.Annotations

[Lindar90]

LGTM