fix(AdvancedMagnifyTool): Exceptions are no longer thrown for the AdvancedMagnifyTool

[jbocce]

Context

#2412

Changes & Results

Upon investigation, it was determined that in part changes in #2322 contributed to #2412. So we only set the active segment index if there is a segmentation representation.

Further investigation showed that the AdvancedMagnifyTool has NOT been working on volume viewports for at least since February of 2025. In general, the click to apply the AdvancedMagnifyTool on a volume viewport would immediately throw an exception. So, in AdvancedMagnifyTool, we now use better detection for segmentation actors. Now the exception is gone, the magnify glass is displayed, but behaviour is still not equivalent to that for a stack viewport. A new issue will be logged soon.

See #2428.

Testing

See #2412

Checklist

PR

• My Pull Request title is descriptive, accurate and follows the
  semantic-release format and guidelines.

Code

• My code has been well-documented (function documentation, inline comments,
  etc.)

Public Documentation Updates

• The documentation page has been updated as necessary for any public API
  additions or removals.

Tested Environment

• "OS: Windows 11
• "Node version: 23.9.0
• "Browser: Chrome 141.0.7390.123

[jbocce]

The changes in this file fix an exception being thrown for volume viewports that was occurring at least since commit e1b5bc6 (Feb 28, 2025), but likely has existed longer. However even with these changes the magnify glass still does not behave like it does for stack viewports.

See #2428

[maxcomperatore]

beautifully done