Copilot Summary

This pull request includes changes to the src/diff.rs file to handle the case of "No newline at end of file" in diffs. The most important changes include adding a new variant to the LineDiff enum, updating the ChunkDiff struct and its methods to remove the no_eof_newline field, and modifying the Display implementations accordingly.

Enhancements to LineDiff enum:

• Added NoNewlineAtEndOfFile variant to the LineDiff enum.
• Updated the FromStr implementation for LineDiff to handle the new variant.
• Updated the Display implementation for LineDiff to properly display the new variant.

Modifications to ChunkDiff struct:

• Removed the no_eof_newline field from the ChunkDiff struct.
• Updated the ChunkDiff methods to remove handling of the no_eof_newline field. [1] [2]
• Updated the Display implementation for ChunkDiff to remove the display logic for the no_eof_newline field.

Additional updates:

• Added a test case to check for the "No newline at end of file" scenario in diffs.
• Updated the DiffTreeNodeContent implementation for LineDiff to include the new variant.