Incorrect results in unescape

[hadeeb]

Describe the bug
unescape function produce incorrect result when the intermediate string generated includes an escape sequence.

Examples

const validator = require('validator');

validator.unescape(validator.escape('<'))

// Expected: '<'
// Actual: '<'

Demo: Stackblitz

Additional context
Validator.js version: 13.6.0
Node.js version: 14.16.0
OS platform: linux, macOS

Suggested solution
& -> & transform should be the last transform in unescape.

Demo: Stackblitz

[Marcholio]

I submitted a PR that fixes this issue (#1835) .