Refactor virtual model creation logic in MoveLinesCommand

[SalerSimo]

Fix #214879
I refactored the virtual model creation logic. I noticed that the logic used for tokenization.getLineTokens and for getLineContent is largely the same, so I introduced a createVirtualModel method that reuses this shared logic. I also added an optional argument to handle cases where the logic for tokenization.getLineTokens and getLineContent differs.

[Copilot]

Pull request overview

This PR refactors the virtual model creation logic in MoveLinesCommand to eliminate code duplication. The refactoring introduces a reusable createVirtualModel method that consolidates the shared logic previously duplicated in three separate locations, with an optional contentOverride parameter to handle cases where line content needs customization.

Key Changes

• Introduced createVirtualModel helper method that encapsulates virtual model creation with configurable line number mapping
• Replaced three inline virtual model definitions with calls to the new helper method
• Added contentOverride parameter to allow custom content for specific lines while maintaining the same tokenization logic