[Security] Encrypt JWT tokens Payload and make it JWE

The application utilizes local storage for storing JWT’s generated by OKTA. The JWT may contain PII or other sensitive data and should be encrypted when being stored in local storage. 
JWE’s represent encrypted jwt tokens. It is a specification to follow for encrypting the token.
This RFC points to signing then encrypting the JWT: https://www.rfc-editor.org/rfc/rfc7519#section-11.2 