Fix safeReplace to replace all matches

[hiSandog]

Summary

• update safeReplace to replace every matching occurrence instead of only the first
• add coverage for replacing multiple matches and keeping dollar signs literal in replacement text

Validation

• env PATH=/Users/sandog/.real/.bin:/usr/local/bin:/opt/homebrew/bin:/usr/bin:/bin:/usr/sbin:/sbin /Users/sandog/.real/.bin/bun test common/src/util/tests/string.test.ts