Fix: Inactive styles being unintentionally overwritten in copyActiveToInactiveIfNotProvided

[stada526]

Context

The copyActiveToInactiveIfNotProvided method ensures that inactive segmentation styles inherit values from their active counterparts when not explicitly set. However, the previous implementation always assigned values, even when an inactive style property was already defined. This led to unintentional overwriting of user-defined inactive styles.

Changes & Results

• Replaced direct assignments with nullish coalescing assignment (??=) to only assign values when the inactive properties are null or undefined.

Testing

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.)

• I have run the yarn build:update-api to update the API documentation, and have
  committed the changes to this PR. (Read more here https://www.cornerstonejs.org/docs/contribute/update-api)

Public Documentation Updates

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

Tested Environment

• "OS: maxOS 15.1
• "Node version: v21.7.1
• "Browser: 130.0.6723.117

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[sedghi]

Great thanks!