Make text annotation cursor scale with viewer zoom level

[mvineeta]

When using the Text annotation tool, the viewer correctly shows a text cursor when adding text. However, when zooming in or out of the viewer, the cursor remains the same size, which makes it:

• Too small when zoomed in
• Too large and obstructive when zoomed out

🎯 Expected Behavior:

• The text cursor should scale proportionally with the viewer zoom level, just like the text being typed.
• This ensures consistent usability regardless of zoom.
• Mimics behavior in tools like Photoshop, Nuke, and others where annotation tools adapt to zoom.

🧪 How to Reproduce:

• Activate the Text annotation tool.
• Start typing in the viewer.
• Zoom in or out using the mouse scroll.
• Observe that the text cursor does not change size.