Preserves a quoted value as written

All 4 scenarios hold

The formatter never rewrites quoting. A quoted value keeps its quote style. A pipe inside quotes does not split the cell. A backslash sequence stays literal.

Three kinds of value have no row here, because each one breaks the parsing of this table. They are a value that mixes both quote styles, a value with unmatched quotes, and a value that holds quoted list elements. The plain tests below cover all three.