Sim Serial Number(ICCID) Validator

# Description

It takes in ICCID (Integrated Circuit Card Identifier) values as input from the user and predicts if it is a valid sim serial number or not. The algorithm to be used is the **Luhn Algorithm**.

This algorithm is used to calculate the check digit on SIM card numbers.

Refer - [Luhn Algorithm](https://en.wikipedia.org/wiki/Luhn_algorithm)

## Language

- [x] C++
- [x] Javascript
- [x] Python
- [x] PHP
- [ ] Other (Please specify)

## Type of issue

- [x] Feature
- [ ] Bug

The checklist will be updated by the maintainers / author of this issue according to the language in which snippets are added or are proposed to be added.