Fix negative zero sign erasure

[jeparlefrancais]

Closes #216

This avoids the issue were the evaluator was replacing -0 results with only 0.

• add entry to the changelog

[github-actions]

Coverage after merging preserve-zero-sign into main will be

87.04%

Coverage Report for Changed Files

File	Stmts	Branches	Funcs	Lines	Uncovered Lines
src/nodes/expressions
mod.rs	76.29%	100%	75.68%	76.43%	138–140, 144–146, 150–152, 156–158, 162–164, 168–170, 186–188, 192–194, 270, 322–325, 327, 92–97
src/process/evaluator
mod.rs	88.01%	100%	98.18%	86.80%	102–103, 164, 176, 187, 198, 207–209, 217, 219–221, 223–224, 227, 239–241, 253–257, 261–262, 264–266, 306, 327, 341, 365, 368, 401, 407–408, 413, 427, 430, 448, 552, 556, 58–60, 71, 827, 88–89