adding more countries to isMobilePhone.js

[RahulSingh044]

Overview

This pull request enhances the isMobilePhone functionality by adding support for mobile phone number validation for several additional countries. The goal is to expand the reach of our validation library and ensure it accommodates a wider range of international phone formats.

Changes Made

New Countries Added : Introduced regex patterns for the following countries:

• Germany (de-DE)
• Vanuatu (en-VU)
• Monaco (fr-MC)
• Liechtenstein (de-LI)
• Côte d'Ivoire (fr-CI)
• Eswatini (en-SZ)

Regex Patterns: Implemented specific regular expressions tailored to the mobile number formats of each newly added country, ensuring accurate validation.

Checklist

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

[rubiin]

please add tests and reference and update the checklist