feat:CHARTS-3248 Custom JWT sample *Ported*

[andym03]

JIRA ticket link

Task: 📈 CHARTS-3248

Description

A new demo for authenticated embedding. Shows off Custom JWT Provider settings in action. A simple login (username: admin, password: password) kicks off a JWT signing process, and said function is passed along to the SDK where the magic happens.

Featues

• 📈 Render an embedded chart on a web page
• 🔒 Only render charts to valid users
• 🔑 Custom JWT authentication via jsonwebtoken

Screencast