tools: Add no useless regex char class rule

Eslint Rule:
Disallow useless escape in regex character class
with optional override characters option and auto
fixable with eslint --fix option.

Usage:
no-useless-regex-char-class-escape: [2, { override: ['[', ']'] }]

PR-URL: https://github.com/nodejs/node/pull/9591


Reviewed-By: Teddy Katz <teddy.katz@gmail.com>