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# Description
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This PR makes the `Display` implementation for `CellPath` show a `?`
suffix on every optional entry, which makes the output consistent with
the language syntax.
Before this PR, the printing of cell paths was confusing, e.g. `$.x` and
`$.x?` were both printed as `x`. Now, the second one is printed as `x?`.
# User-Facing Changes
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The formatting of cell paths now matches the syntax used to create them,
reducing confusion.
# Tests + Formatting
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All tests pass, including `stdlib` tests.
# After Submitting
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