fix(isCreditCard): anchor Mastercard regex alternation

[xxiaoxiong]

Problem

isCreditCard("5108") returns true because the Mastercard regex:

/^5[1-5][0-9]{2}|(222[1-9]|22[3-9][0-9]|2[3-6][0-9]{2}|27[01][0-9]|2720)[0-9]{12}$/

has an anchoring bug: | binds weaker than ^ and $, so the regex is parsed as:

1. ^5[1-5][0-9]{2} — start-anchored only, matches any 4+ digit string starting with 51-55
2. (...)[0-9]{12}$ — end-anchored only

Fix

Wrapped the alternation in a non-capturing group:

/^(?:5[1-5][0-9]{2}|222[1-9]|22[3-9][0-9]|2[3-6][0-9]{2}|27[01][0-9]|2720)[0-9]{12}$/

Also fixed the same issue in the unionpay regex.

Fixes #2717