feat: add email notification feature for user errors

[meness]

Changes

• Implement MailService to handle email sending using nodemailer and express-handlebars.
• Introduce UserErrorEvent to manage user error events and trigger email notifications.
• Add listenUserError listener to handle user error events and send emails based on configuration.
• Update handlers to include configuration in their operations.
• Extend configuration schema to support email notifications for errors.
• Add new dependencies for email handling and template linting.
• Update linting and formatting scripts to include handlebars files.