Fixes #1686

The format for passport numbers for CN passports are as follows:

• Starts with either a "G" (for Ordinary) or an "E" (for Electronic)
• If it starts with "G", 8 numbers follow
• If it starts with "E" either 8 numbers follow, or a letter [A-Z] (except "I" or "O") and 7 numbers follow

Valid Examples:

• G12345678
• E12345678
• EA1234567

So the above conditions were implemented with the following regex : ^G\d{8}$|^E(?![IO])[A-Z0-9]\d{7}$

The appropriate testes were added to validators.js with all of them passing.

Checklist

• PR contains only changes related; no stray files, etc.
• README updated (where applicable)
• Tests written (where applicable)