Wrap all lines in diffs after Copilot edits

When wrapping lines in a document, when Copilot's changes are applied, only the unchanged line is wrapped. The change line is unwrapped. This make it hard to understand what's been changed.

Ideally, when line wrapping is enabled, both the original and changed line should remain wrapped for easy comparison.

Reproduce the issue in VS Code's diff editor with line wrapping enabled, then apply a Copilot edit and compare the unchanged and changed lines. Trace the diff-rendering and wrapping entry points involved; done means both sides of the diff remain wrapped after the edit and the comparison is readable.

Written by the indexing model from the issue text.