Jwt expiration verify

[VatsalBhuva11]

Changes

feat(isJWTExpired): check if a JWT token is expired or not by comparing with the current time and the expiration time. Returns true if the token is expired/invalid, and false if it is a valid token that has not expired or has no expiration set.

Process

I created a separate validator called isJWTExpired.js, that checks if a given JWT Token is beyond it's expiry or not. It also makes use of the isJWT validator to check if the string is a valid JWT token in the first place or not. Post that, I've checked whether the current time has exceeded the expiration time, which indicates that the token has expired.

Feat: #2298

Checklist

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